code: protected function mutateValue($value, $dir = 'setter')
      {
          $mutator = $this->getMutator($value, $dir, $this->attributes['meta_type']);
  
          if (method_exists($this, $mutator)) {
              return $this->{$mutator}($value);
          }
  
          return static::$attributeMutator->mutate($value, $mutator);
      }
docs: Mutate attribute value.
  
  @param  mixed  $value
  @param  string $dir
  @return mixed