protected function invalidOperator($operator)
    {
        return ! in_array(strtolower($operator), $this->operators, true) &&
               ! in_array(strtolower($operator), $this->grammar->getOperators(), true);
    }
protected function invalidOperator($operator)
    {
        return ! in_array(strtolower($operator), $this->operators, true) &&
               ! in_array(strtolower($operator), $this->grammar->getOperators(), true);
    }
protected function invalidOperator ( $ operator ) { return ! in_array ( strtolower ( $ operator ) , $ this -> operators , true ) && ! in_array ( strtolower ( $ operator ) , $ this -> grammar -> getOperators ( ) , true ) ; }
Determine if the given operator is supported.

@param  string  $operator
@return bool
Determine if the given operator is supported .