public function setField($field)
    {
        if (Format::isString256($field) === true) {
            $this->field = $field;
        } else {
            $msg = "The 'field' argument must be a non-empty string, '" . gettype($field) . "' given.";
            throw new InvalidArgumentException($msg);
        }
    }
public function setField($field)
    {
        if (Format::isString256($field) === true) {
            $this->field = $field;
        } else {
            $msg = "The 'field' argument must be a non-empty string, '" . gettype($field) . "' given.";
            throw new InvalidArgumentException($msg);
        }
    }
public function setField ( $ field ) { if ( Format :: isString256 ( $ field ) === true ) { $ this -> field = $ field ; } else { $ msg = "The 'field' argument must be a non-empty string, '" . gettype ( $ field ) . "' given." ; throw new InvalidArgumentException ( $ msg ) ; } }
Set the field specifier to use when displaying variables of record cardinality. Give an
empty string if no field is indicated.

@param string $field A string with at most 256 characters.
@throws \InvalidArgumentException If $field is not a string with at most 256 characters.
Set the field specifier to use when displaying variables of record cardinality . Give an empty string if no field is indicated .