public static function validate($argument, $argumentName = null)
    {
        if (trim($argument) != null && !is_numeric($argument)) {
            throw new \InvalidArgumentException("$argumentName is not a valid numeric value");
        }
        return true;
    }
public static function validate($argument, $argumentName = null)
    {
        if (trim($argument) != null && !is_numeric($argument)) {
            throw new \InvalidArgumentException("$argumentName is not a valid numeric value");
        }
        return true;
    }
public static function validate ( $ argument , $ argumentName = null ) { if ( trim ( $ argument ) != null && ! is_numeric ( $ argument ) ) { throw new \ InvalidArgumentException ( "$argumentName is not a valid numeric value" ) ; } return true ; }
Helper method for validating an argument if it is numeric

@param mixed     $argument
@param string|null $argumentName
@return bool
Helper method for validating an argument if it is numeric