Fix phpdoc @param tags with the NULL type

Parameters documented by "@param null" make it difficult for IDEs and
static analysis tools to reason about the code.

Author: wulff

src/Transformation/Adjustment/Improve.php

@@ -31,8 +31,8 @@ class Improve extends BlendEffectQualifier
     /**
      * Improve constructor.
      *
-     * @param      $blend
-     * @param null $mode
+     * @param       $blend
+     * @param mixed $mode
      */
     public function __construct($blend = null, $mode = null)
     {

src/Transformation/Background/AutoGradientBackground.php

@@ -44,7 +44,7 @@ class AutoGradientBackground extends AutoBackground
      *
      * @param string     $mode              The auto background mode.
      * @param int|string $gradientColors    The number of gradient colors to select. Possible values: 2 or 4. Default: 2
-     * @param null       $gradientDirection The direction. Use the constants defined in the GradientDirection class.
+     * @param string     $gradientDirection The direction. Use the constants defined in the GradientDirection class.
      */
     public function __construct($mode, $gradientColors = null, $gradientDirection = null)
     {

src/Transformation/Border/BorderValue.php

@@ -28,9 +28,9 @@ class BorderValue extends QualifierMultiValue
     /**
      * BorderValue constructor.
      *
-     * @param null $color
-     * @param null $width
-     * @param null $style
+     * @param string     $color
+     * @param int|string $width
+     * @param string     $style
      */
     public function __construct($color = null, $width = null, $style = null)
     {

src/Transformation/CommonTransformation.php

@@ -28,7 +28,7 @@ class CommonTransformation extends BaseComponent implements CommonTransformation
     /**
      * CommonTransformation constructor.
      *
-     * @param null $transformation
+     * @param mixed $transformation
      */
     public function __construct($transformation = null)
     {

src/Transformation/CustomFunction/CustomFunctionValue.php

@@ -23,9 +23,9 @@ class CustomFunctionValue extends QualifierMultiValue
     /**
      * CustomFunctionValue constructor.
      *
-     * @param null $source
-     * @param null $type
-     * @param null $preprocess
+     * @param mixed $source
+     * @param mixed $type
+     * @param mixed $preprocess
      */
     public function __construct($source = null, $type = null, $preprocess = null)
     {

src/Transformation/Delivery/Quality/QualityQualifier.php

@@ -10,6 +10,7 @@
 
 namespace Cloudinary\Transformation;
 
+use Cloudinary\Transformation\BaseComponent;
 use Cloudinary\Transformation\Qualifier\BaseExpressionQualifier;
 
 /**
@@ -60,9 +61,9 @@ class QualityQualifier extends BaseExpressionQualifier
     /**
      * Quality constructor.
      *
-     * @param       $strength
-     * @param null  $preset
-     * @param array $values
+     * @param mixed               $strength
+     * @param mixed|BaseComponent $preset
+     * @param mixed               $values
      */
     public function __construct($strength, $preset = null, ...$values)
     {

src/Transformation/Effect/Color/AssistColorBlind.php

@@ -22,7 +22,7 @@ class AssistColorBlind extends LimitedEffectQualifier
     /**
      * AssistColorBlind constructor.
      *
-     * @param null $strength
+     * @param string $strength
      */
     public function __construct($strength = null)
     {

src/Transformation/Effect/Color/SimulateColorBlind.php

@@ -53,7 +53,7 @@ class SimulateColorBlind extends ValueEffectQualifier
     /**
      * SimulateColorBlind constructor.
      *
-     * @param null $condition
+     * @param string $condition
      */
     public function __construct($condition = null)
     {

src/Transformation/Effect/EffectActionTrait.php

@@ -31,9 +31,9 @@ public static function named($name, ...$args)
     }
 
     /**
-     * @param       $effectName
-     * @param null  $value
-     * @param mixed ...$args
+     * @param string $effectName
+     * @param mixed  $value
+     * @param mixed  ...$args
      *
      * @return EffectAction
      */
@@ -43,10 +43,10 @@ public static function valued($effectName, $value = null, ...$args)
     }
 
     /**
-     * @param       $effectName
-     * @param       $range
-     * @param null  $value
-     * @param mixed ...$args
+     * @param string $effectName
+     * @param array  $range
+     * @param mixed  $value
+     * @param mixed  ...$args
      *
      * @return EffectAction
      */
@@ -56,10 +56,10 @@ public static function limited($effectName, $range, $value = null, ...$args)
     }
 
     /**
-     * @param       $effectName
-     * @param       $range
-     * @param null  $value
-     * @param mixed ...$args
+     * @param string $effectName
+     * @param array  $range
+     * @param mixed  $value
+     * @param mixed  ...$args
      *
      * @return LevelEffectAction
      */
@@ -69,10 +69,10 @@ public static function withLevel($effectName, $range, $value = null, ...$args)
     }
 
     /**
-     * @param       $effectName
-     * @param       $range
-     * @param null  $value
-     * @param mixed ...$args
+     * @param string $effectName
+     * @param array  $range
+     * @param mixed  $value
+     * @param mixed  ...$args
      *
      * @return StrengthEffectAction
      */
@@ -82,10 +82,10 @@ public static function withStrength($effectName, $range, $value = null, ...$args
     }
 
     /**
-     * @param       $effectName
-     * @param       $range
-     * @param null  $value
-     * @param mixed ...$args
+     * @param string $effectName
+     * @param array  $range
+     * @param mixed  $value
+     * @param mixed  ...$args
      *
      * @return BlendEffectAction
      */
@@ -95,10 +95,10 @@ public static function withBlend($effectName, $range, $value = null, ...$args)
     }
 
     /**
-     * @param       $effectName
-     * @param       $range
-     * @param null  $value
-     * @param mixed ...$args
+     * @param string $effectName
+     * @param array  $range
+     * @param mixed  $value
+     * @param mixed  ...$args
      *
      * @return ThresholdEffectAction
      */
@@ -108,9 +108,9 @@ public static function withThreshold($effectName, $range, $value = null, ...$arg
     }
 
     /**
-     * @param       $effectName
-     * @param null  $value
-     * @param mixed ...$args
+     * @param string $effectName
+     * @param mixed  $value
+     * @param mixed  ...$args
      *
      * @return DurationEffectAction
      */
@@ -120,9 +120,9 @@ public static function withDuration($effectName, $value = null, ...$args)
     }
 
     /**
-     * @param       $effectName
-     * @param null  $value
-     * @param mixed ...$args
+     * @param string $effectName
+     * @param array  $value
+     * @param mixed  ...$args
      *
      * @return ToleranceEffectAction
      */

src/Transformation/Effect/LimitedEffectQualifier.php

@@ -29,10 +29,10 @@ class LimitedEffectQualifier extends ValueEffectQualifier
     /**
      * LimitedEffectQualifier constructor.
      *
-     * @param       $effectName
-     * @param       $range
-     * @param       $level
-     * @param array $args
+     * @param string $effectName
+     * @param array  $range
+     * @param mixed  $level
+     * @param array  $args
      */
     public function __construct($effectName, $range, $level = null, ...$args)
     {