src/ComposerExtra.php
protected function merge($target, $source)
    {
        if ($source === null) {
            return $target;
        }

        return call_user_func($this->merge, $target, $source);
    }
protected function merge($target, $source)
    {
        if ($source === null) {
            return $target;
        }

        return call_user_func($this->merge, $target, $source);
    }
protected function merge ( $ target , $ source ) { if ( $ source === null ) { return $ target ; } return call_user_func ( $ this -> merge , $ target , $ source ) ; }
Merge two configs.

@param mixed $target Target config
@param mixed $source Source config

@return mixed The merged config
Merge two configs .