src/Validator/Validator.php
protected function isCallable($arg, $method = null)
    {
        if (is_callable($arg) || is_callable([$arg, $method]) || $this->isClass($arg)) {
            return true;
        }

        return false;
    }
protected function isCallable($arg, $method = null)
    {
        if (is_callable($arg) || is_callable([$arg, $method]) || $this->isClass($arg)) {
            return true;
        }

        return false;
    }
protected function isCallable ( $ arg , $ method = null ) { if ( is_callable ( $ arg ) || is_callable ( [ $ arg , $ method ] ) || $ this -> isClass ( $ arg ) ) { return true ; } return false ; }
Checks if the specified argument is a valid callable.

@param mixed $arg The argument to validate.

@return bool True if the specified argument is valid. False if it does not.
Checks if the specified argument is a valid callable .