diff --git a/lib/PayPal/Cache/AuthorizationCache.php b/lib/PayPal/Cache/AuthorizationCache.php
index 46e86fd..83910d3 100644
--- a/lib/PayPal/Cache/AuthorizationCache.php
+++ b/lib/PayPal/Cache/AuthorizationCache.php
@@ -20,7 +20,9 @@ abstract class AuthorizationCache
     public static function pull($config = null, $clientId = null)
     {
         // Return if not enabled
-        if (!self::isEnabled($config)) { return null; }
+        if (!self::isEnabled($config)) {
+            return null;
+        }
 
         $tokens = null;
         $cachePath = self::cachePath($config);
@@ -32,7 +34,7 @@ abstract class AuthorizationCache
                 if ($clientId && is_array($tokens) && array_key_exists($clientId, $tokens)) {
                     // If client Id is found, just send in that data only
                     return $tokens[$clientId];
-                } else if ($clientId) {
+                } elseif ($clientId) {
                     // If client Id is provided, but no key in persisted data found matching it.
                     return null;
                 }
@@ -54,7 +56,9 @@ abstract class AuthorizationCache
     public static function push($config = null, $clientId, $accessToken, $tokenCreateTime, $tokenExpiresIn)
     {
         // Return if not enabled
-        if (!self::isEnabled($config)) { return; }
+        if (!self::isEnabled($config)) {
+            return;
+        }
 
         $cachePath = self::cachePath($config);
         if (!is_dir(dirname($cachePath))) {
@@ -74,7 +78,7 @@ abstract class AuthorizationCache
                 'tokenExpiresIn' => $tokenExpiresIn
             );
         }
-        if(!file_put_contents($cachePath, json_encode($tokens))) {
+        if (!file_put_contents($cachePath, json_encode($tokens))) {
             throw new \Exception("Failed to write cache");
         };
     }
@@ -116,6 +120,4 @@ abstract class AuthorizationCache
         $config = ($config && is_array($config)) ? $config : PayPalConfigManager::getInstance()->getConfigHashmap();
         return (array_key_exists($key, $config)) ? trim($config[$key]) : null;
     }
-
-
 }
diff --git a/lib/PayPal/Common/PayPalModel.php b/lib/PayPal/Common/PayPalModel.php
index fdfaba8..78734ef 100644
--- a/lib/PayPal/Common/PayPalModel.php
+++ b/lib/PayPal/Common/PayPalModel.php
@@ -1,6 +1,7 @@
 <?php
 
 namespace PayPal\Common;
+
 use PayPal\Validation\JsonValidator;
 use PayPal\Validation\ModelAccessorValidator;
 
@@ -67,7 +68,9 @@ class PayPalModel
     public static function getList($data)
     {
         // Return Null if Null
-        if ($data === null) { return null; }
+        if ($data === null) {
+            return null;
+        }
 
         if (is_a($data, get_class(new \stdClass()))) {
             //This means, root element is object
@@ -173,9 +176,9 @@ class PayPalModel
         foreach ($param as $k => $v) {
             if ($v instanceof PayPalModel) {
                 $ret[$k] = $v->toArray();
-            } else if (sizeof($v) <= 0 && is_array($v)) {
+            } elseif (sizeof($v) <= 0 && is_array($v)) {
                 $ret[$k] = array();
-            } else if (is_array($v)) {
+            } elseif (is_array($v)) {
                 $ret[$k] = $this->_convertToArray($v);
             } else {
                 $ret[$k] = $v;
@@ -204,9 +207,9 @@ class PayPalModel
                 // If the value is an array, it means, it is an object after conversion
                 if (is_array($v)) {
                     // Determine the class of the object
-                    if (($clazz = ReflectionUtil::getPropertyClass(get_class($this), $k)) != null){
+                    if (($clazz = ReflectionUtil::getPropertyClass(get_class($this), $k)) != null) {
                         // If the value is an associative array, it means, its an object. Just make recursive call to it.
-                        if (empty($v)){
+                        if (empty($v)) {
                             if (ReflectionUtil::isPropertyClassArray(get_class($this), $k)) {
                                 // It means, it is an array of objects.
                                 $this->assignValue($k, array());
diff --git a/lib/PayPal/Common/PayPalResourceModel.php b/lib/PayPal/Common/PayPalResourceModel.php
index 18ddb38..927a379 100644
--- a/lib/PayPal/Common/PayPalResourceModel.php
+++ b/lib/PayPal/Common/PayPalResourceModel.php
@@ -115,4 +115,4 @@ class PayPalResourceModel extends PayPalModel implements IResource
         $apiContext = $apiContext ? $apiContext : new ApiContext(self::$credential);
         $apiContext->getCredential()->updateAccessToken($apiContext->getConfig(), $refreshToken);
     }
-} 
+}
diff --git a/lib/PayPal/Common/PayPalUserAgent.php b/lib/PayPal/Common/PayPalUserAgent.php
index d072b2f..c3131ed 100644
--- a/lib/PayPal/Common/PayPalUserAgent.php
+++ b/lib/PayPal/Common/PayPalUserAgent.php
@@ -21,7 +21,6 @@ class PayPalUserAgent
      */
     public static function getValue($sdkName, $sdkVersion)
     {
-
         $featureList = array(
             'platform-ver=' . PHP_VERSION,
             'bit=' . self::_getPHPBit(),
diff --git a/lib/PayPal/Common/ReflectionUtil.php b/lib/PayPal/Common/ReflectionUtil.php
index 0b92a5c..f7b397a 100644
--- a/lib/PayPal/Common/ReflectionUtil.php
+++ b/lib/PayPal/Common/ReflectionUtil.php
@@ -1,6 +1,7 @@
 <?php
 
 namespace PayPal\Common;
+
 use PayPal\Exception\PayPalConfigurationException;
 
 /**
@@ -112,7 +113,7 @@ class ReflectionUtil
         }
 
         // todo: smarter regexp
-        if ( !preg_match_all(
+        if (!preg_match_all(
             '~\@([^\s@\(]+)[\t ]*(?:\(?([^\n@]+)\)?)?~i',
             $refl->getDocComment(),
             $annots,
@@ -120,7 +121,7 @@ class ReflectionUtil
             return null;
         }
         foreach ($annots[1] as $i => $annot) {
-            $annotations[strtolower($annot)] = empty($annots[2][$i]) ? TRUE : rtrim($annots[2][$i], " \t\n\r)");
+            $annotations[strtolower($annot)] = empty($annots[2][$i]) ? true : rtrim($annots[2][$i], " \t\n\r)");
         }
 
         return $annotations;
diff --git a/lib/PayPal/Converter/FormatConverter.php b/lib/PayPal/Converter/FormatConverter.php
index e564742..a237766 100644
--- a/lib/PayPal/Converter/FormatConverter.php
+++ b/lib/PayPal/Converter/FormatConverter.php
@@ -53,7 +53,7 @@ class FormatConverter
                 throw new \InvalidArgumentException("value cannot have decimals for $currency currency");
             }
             $decimals = $currencyDecimals[$currency];
-        } else if (strpos($value, ".") === false) {
+        } elseif (strpos($value, ".") === false) {
             // Check if value has decimal values. If not no need to assign 2 decimals with .00 at the end
             $decimals = 0;
         }
diff --git a/lib/PayPal/Core/PayPalConfigManager.php b/lib/PayPal/Core/PayPalConfigManager.php
index f884df4..a7ee1ca 100644
--- a/lib/PayPal/Core/PayPalConfigManager.php
+++ b/lib/PayPal/Core/PayPalConfigManager.php
@@ -95,7 +95,6 @@ class PayPalConfigManager
      */
     public function get($searchKey)
     {
-
         if (array_key_exists($searchKey, $this->configs)) {
             return $this->configs[$searchKey];
         } else {
@@ -108,7 +107,6 @@ class PayPalConfigManager
 
             return $arr;
         }
-
     }
 
     /**
@@ -123,7 +121,6 @@ class PayPalConfigManager
      */
     public function getIniPrefix($userId = null)
     {
-
         if ($userId == null) {
             $arr = array();
             foreach ($this->configs as $key => $value) {
@@ -157,7 +154,4 @@ class PayPalConfigManager
     {
         trigger_error('Clone is not allowed.', E_USER_ERROR);
     }
-
 }
-
-    
diff --git a/lib/PayPal/Core/PayPalCredentialManager.php b/lib/PayPal/Core/PayPalCredentialManager.php
index 77a884e..8f1edd6 100644
--- a/lib/PayPal/Core/PayPalCredentialManager.php
+++ b/lib/PayPal/Core/PayPalCredentialManager.php
@@ -113,7 +113,6 @@ class PayPalCredentialManager
             $suffix++;
             $key = $prefix . $suffix;
         }
-
     }
 
     /**
@@ -146,7 +145,7 @@ class PayPalCredentialManager
     {
         if ($userId == null && array_key_exists($this->defaultAccountName, $this->credentialHashmap)) {
             $credObj = $this->credentialHashmap[$this->defaultAccountName];
-        } else if (array_key_exists($userId, $this->credentialHashmap)) {
+        } elseif (array_key_exists($userId, $this->credentialHashmap)) {
             $credObj = $this->credentialHashmap[$userId];
         }
 
@@ -164,5 +163,4 @@ class PayPalCredentialManager
     {
         trigger_error('Clone is not allowed.', E_USER_ERROR);
     }
-
 }
diff --git a/lib/PayPal/Core/PayPalHttpConfig.php b/lib/PayPal/Core/PayPalHttpConfig.php
index 6bd4454..8a2b2a3 100644
--- a/lib/PayPal/Core/PayPalHttpConfig.php
+++ b/lib/PayPal/Core/PayPalHttpConfig.php
@@ -21,7 +21,7 @@ class PayPalHttpConfig
     public static $defaultCurlOptions = array(
         CURLOPT_SSLVERSION => 6,
         CURLOPT_CONNECTTIMEOUT => 10,
-        CURLOPT_RETURNTRANSFER => TRUE,
+        CURLOPT_RETURNTRANSFER => true,
         CURLOPT_TIMEOUT => 60,    // maximum number of seconds to allow cURL functions to execute
         CURLOPT_USERAGENT => 'PayPal-PHP-SDK',
         CURLOPT_HTTPHEADER => array(),
diff --git a/lib/PayPal/Core/PayPalHttpConnection.php b/lib/PayPal/Core/PayPalHttpConnection.php
index ea0dffd..7e809ec 100644
--- a/lib/PayPal/Core/PayPalHttpConnection.php
+++ b/lib/PayPal/Core/PayPalHttpConnection.php
@@ -55,7 +55,6 @@ class PayPalHttpConnection
      */
     private function getHttpHeaders()
     {
-
         $ret = array();
         foreach ($this->httpConfig->getHeaders() as $k => $v) {
             $ret[] = "$k: $v";
@@ -78,8 +77,8 @@ class PayPalHttpConnection
         //Initialize Curl Options
         $ch = curl_init($this->httpConfig->getUrl());
         $options = $this->httpConfig->getCurlOptions();
-        if(empty($options[CURLOPT_HTTPHEADER])) {
-            unset ($options[CURLOPT_HTTPHEADER]);
+        if (empty($options[CURLOPT_HTTPHEADER])) {
+            unset($options[CURLOPT_HTTPHEADER]);
         }
         curl_setopt_array($ch, $options);
         curl_setopt($ch, CURLOPT_URL, $this->httpConfig->getUrl());
@@ -101,7 +100,7 @@ class PayPalHttpConnection
         }
 
         //Default Option if Method not of given types in switch case
-        if ($this->httpConfig->getMethod() != NULL) {
+        if ($this->httpConfig->getMethod() != null) {
             curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $this->httpConfig->getMethod());
         }
 
@@ -174,14 +173,14 @@ class PayPalHttpConnection
                 "Retried $retries times." . $result);
             $this->logger->debug("\n\n" . str_repeat('=', 128) . "\n");
             throw $ex;
-        } else if ($httpStatus < 200 || $httpStatus >= 300) {
+        } elseif ($httpStatus < 200 || $httpStatus >= 300) {
             $ex = new PayPalConnectionException(
                 $this->httpConfig->getUrl(),
                 "Got Http response code $httpStatus when accessing {$this->httpConfig->getUrl()}.",
                 $httpStatus
             );
             $ex->setData($result);
-            $this->logger->error("Got Http response code $httpStatus when accessing {$this->httpConfig->getUrl()}. " . $result );
+            $this->logger->error("Got Http response code $httpStatus when accessing {$this->httpConfig->getUrl()}. " . $result);
             $this->logger->debug("\n\n" . str_repeat('=', 128) . "\n");
             throw $ex;
         }
@@ -191,5 +190,4 @@ class PayPalHttpConnection
         //Return result object
         return $result;
     }
-
 }
diff --git a/lib/PayPal/Core/PayPalLoggingManager.php b/lib/PayPal/Core/PayPalLoggingManager.php
index b9e5892..90521a8 100644
--- a/lib/PayPal/Core/PayPalLoggingManager.php
+++ b/lib/PayPal/Core/PayPalLoggingManager.php
@@ -116,5 +116,4 @@ class PayPalLoggingManager
             $this->logger->debug($message);
         }
     }
-
 }
diff --git a/lib/PayPal/Exception/PayPalInvalidCredentialException.php b/lib/PayPal/Exception/PayPalInvalidCredentialException.php
index 2531f5b..09ad27a 100644
--- a/lib/PayPal/Exception/PayPalInvalidCredentialException.php
+++ b/lib/PayPal/Exception/PayPalInvalidCredentialException.php
@@ -32,5 +32,4 @@ class PayPalInvalidCredentialException extends \Exception
             . ': <b>' . $this->getMessage() . '</b>';
         return $errorMsg;
     }
-
 }
diff --git a/lib/PayPal/Exception/PayPalMissingCredentialException.php b/lib/PayPal/Exception/PayPalMissingCredentialException.php
index 9fac996..6ace3b4 100644
--- a/lib/PayPal/Exception/PayPalMissingCredentialException.php
+++ b/lib/PayPal/Exception/PayPalMissingCredentialException.php
@@ -33,5 +33,4 @@ class PayPalMissingCredentialException extends \Exception
 
         return $errorMsg;
     }
-
 }
diff --git a/lib/PayPal/Handler/OauthHandler.php b/lib/PayPal/Handler/OauthHandler.php
index f281eb0..5411508 100644
--- a/lib/PayPal/Handler/OauthHandler.php
+++ b/lib/PayPal/Handler/OauthHandler.php
@@ -78,9 +78,9 @@ class OauthHandler implements IPayPalHandler
     {
         if (isset($config['oauth.EndPoint'])) {
             $baseEndpoint = $config['oauth.EndPoint'];
-        } else if (isset($config['service.EndPoint'])) {
+        } elseif (isset($config['service.EndPoint'])) {
             $baseEndpoint = $config['service.EndPoint'];
-        } else if (isset($config['mode'])) {
+        } elseif (isset($config['mode'])) {
             switch (strtoupper($config['mode'])) {
                 case 'SANDBOX':
                     $baseEndpoint = PayPalConstants::REST_SANDBOX_ENDPOINT;
diff --git a/lib/PayPal/Handler/RestHandler.php b/lib/PayPal/Handler/RestHandler.php
index ad581d7..ec5298d 100644
--- a/lib/PayPal/Handler/RestHandler.php
+++ b/lib/PayPal/Handler/RestHandler.php
@@ -47,7 +47,6 @@ class RestHandler implements IPayPalHandler
      */
     public function handle($httpConfig, $request, $options)
     {
-
         $credential = $this->apiContext->getCredential();
         $config = $this->apiContext->getConfig();
 
@@ -105,7 +104,7 @@ class RestHandler implements IPayPalHandler
     {
         if (isset($config['service.EndPoint'])) {
             return $config['service.EndPoint'];
-        } else if (isset($config['mode'])) {
+        } elseif (isset($config['mode'])) {
             switch (strtoupper($config['mode'])) {
                 case 'SANDBOX':
                     return PayPalConstants::REST_SANDBOX_ENDPOINT;
diff --git a/lib/PayPal/Log/PayPalDefaultLogFactory.php b/lib/PayPal/Log/PayPalDefaultLogFactory.php
index 1ac894f..3066810 100644
--- a/lib/PayPal/Log/PayPalDefaultLogFactory.php
+++ b/lib/PayPal/Log/PayPalDefaultLogFactory.php
@@ -23,4 +23,4 @@ class PayPalDefaultLogFactory implements PayPalLogFactory
     {
         return new PayPalLogger($className);
     }
-}
\ No newline at end of file
+}
diff --git a/lib/PayPal/Log/PayPalLogFactory.php b/lib/PayPal/Log/PayPalLogFactory.php
index ef77318..986adf2 100644
--- a/lib/PayPal/Log/PayPalLogFactory.php
+++ b/lib/PayPal/Log/PayPalLogFactory.php
@@ -13,5 +13,4 @@ interface PayPalLogFactory
      * @return LoggerInterface instance of logger object implementing LoggerInterface
      */
     public function getLogger($className);
-
-}
\ No newline at end of file
+}
diff --git a/lib/PayPal/Log/PayPalLogger.php b/lib/PayPal/Log/PayPalLogger.php
index 17cd229..ed7a80c 100644
--- a/lib/PayPal/Log/PayPalLogger.php
+++ b/lib/PayPal/Log/PayPalLogger.php
@@ -6,7 +6,6 @@ use PayPal\Core\PayPalConfigManager;
 use Psr\Log\AbstractLogger;
 use Psr\Log\LogLevel;
 
-
 class PayPalLogger extends AbstractLogger
 {
 
@@ -75,11 +74,11 @@ class PayPalLogger extends AbstractLogger
 
     public function log($level, $message, array $context = array())
     {
-        if($this->isLoggingEnabled) {
+        if ($this->isLoggingEnabled) {
             // Checks if the message is at level below configured logging level
             if (array_search($level, $this->loggingLevels) <= array_search($this->loggingLevel, $this->loggingLevels)) {
                 error_log("[" . date('d-m-Y h:i:s') . "] " . $this->loggerName . " : " . strtoupper($level) . ": $message\n", 3, $this->loggerFile);
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/lib/PayPal/Security/Cipher.php b/lib/PayPal/Security/Cipher.php
index 3b7b5a8..f95f21b 100644
--- a/lib/PayPal/Security/Cipher.php
+++ b/lib/PayPal/Security/Cipher.php
@@ -18,7 +18,7 @@ class Cipher
      */
     const IV_SIZE = 16;
 
-    function __construct($secretKey)
+    public function __construct($secretKey)
     {
         $this->secretKey = $secretKey;
     }
@@ -29,7 +29,7 @@ class Cipher
      * @param $input
      * @return string
      */
-    function encrypt($input)
+    public function encrypt($input)
     {
         // Create a random IV. Not using mcrypt to generate one, as to not have a dependency on it.
         $iv = substr(uniqid("", true), 0, Cipher::IV_SIZE);
@@ -45,7 +45,7 @@ class Cipher
      * @param $input
      * @return string
      */
-    function decrypt($input)
+    public function decrypt($input)
     {
         // Decode the IV + data
         $input = base64_decode($input);
diff --git a/lib/PayPal/Transport/PayPalRestCall.php b/lib/PayPal/Transport/PayPalRestCall.php
index e80f5ec..f9edf03 100644
--- a/lib/PayPal/Transport/PayPalRestCall.php
+++ b/lib/PayPal/Transport/PayPalRestCall.php
@@ -52,7 +52,6 @@ class PayPalRestCall
      */
     public function execute($handlers = array(), $path, $method, $data = '', $headers = array())
     {
-
         $config = $this->apiContext->getConfig();
         $httpConfig = new PayPalHttpConfig(null, $method, $config);
         $headers = $headers ? $headers : array();
@@ -75,5 +74,4 @@ class PayPalRestCall
 
         return $response;
     }
-
 }
diff --git a/lib/PayPal/Validation/ArgumentValidator.php b/lib/PayPal/Validation/ArgumentValidator.php
index 5f2d3bf..29e7fa3 100644
--- a/lib/PayPal/Validation/ArgumentValidator.php
+++ b/lib/PayPal/Validation/ArgumentValidator.php
@@ -23,7 +23,7 @@ class ArgumentValidator
         if ($argument === null) {
             // Error if Object Null
             throw new \InvalidArgumentException("$argumentName cannot be null");
-        } else if (gettype($argument) == 'string' && trim($argument) == ''){
+        } elseif (gettype($argument) == 'string' && trim($argument) == '') {
             // Error if String Empty
             throw new \InvalidArgumentException("$argumentName string cannot be empty");
         }
diff --git a/lib/PayPal/Validation/JsonValidator.php b/lib/PayPal/Validation/JsonValidator.php
index 1159237..5522ff2 100644
--- a/lib/PayPal/Validation/JsonValidator.php
+++ b/lib/PayPal/Validation/JsonValidator.php
@@ -32,4 +32,4 @@ class JsonValidator
         }
         return true;
     }
-} 
+}
diff --git a/lib/PayPal/Validation/NumericValidator.php b/lib/PayPal/Validation/NumericValidator.php
index 6744528..62fa560 100644
--- a/lib/PayPal/Validation/NumericValidator.php
+++ b/lib/PayPal/Validation/NumericValidator.php
@@ -21,7 +21,6 @@ class NumericValidator
     {
         if (trim($argument) != null && !is_numeric($argument)) {
             throw new \InvalidArgumentException("$argumentName is not a valid numeric value");
-
         }
         return true;
     }
diff --git a/lib/PayPal/Validation/UrlValidator.php b/lib/PayPal/Validation/UrlValidator.php
index ffd195c..1b423f2 100644
--- a/lib/PayPal/Validation/UrlValidator.php
+++ b/lib/PayPal/Validation/UrlValidator.php
@@ -23,4 +23,4 @@ class UrlValidator
             throw new \InvalidArgumentException("$urlName is not a fully qualified URL");
         }
     }
-}
\ No newline at end of file
+}