Crontab\Variable::getHash PHP Method

    public function getHash()
    {
        return hash('md5', serialize(array(strval($this->getName()), strval($this->getValue()))));
    }

 /**
  * @param Variable $variable
  * @return Crontab
  */
 public function removeVariable(Variable $variable)
 {
     unset($this->variables[$variable->getHash()]);
     return $this;
 }