/**
  * Checks if the response is valid
  * @param ShaComposer $shaComposer
  * @return bool
  */
 public function isValid(ShaComposer $shaComposer)
 {
     return $shaComposer->compose($this->parameters) == $this->shaSign;
 }
 /** @return string */
 public function getShaSign()
 {
     return $this->shaComposer->compose($this->toArray());
 }