SDK-766: Declare convertMultiValue() as static and remove unneeded returns

Author: davidgrayston

src/Yoti/Entity/MultiValue.php

@@ -93,7 +93,6 @@ public function filterInstance($type)
         return $this->filter(function ($item) use ($type) {
             return $item instanceof $type;
         });
-        return $this;
     }
 
     /**
@@ -108,7 +107,6 @@ public function filterType($type)
         return $this->filter(function ($item) use ($type) {
             return gettype($item) === $type;
         });
-        return $this;
     }
 
     /**

src/Yoti/Util/Profile/AttributeConverter.php

@@ -91,7 +91,7 @@ private static function convertValueBasedOnContentType($value, $contentType)
      * @param string $value
      * @return MultiValue
      */
-    private function convertMultiValue($value)
+    private static function convertMultiValue($value)
     {
         $protoMultiValue = new \Attrpubapi\MultiValue();
         $protoMultiValue->mergeFromString($value);