public function __isset($key)
    {
        $this->parse();
        if (isset($this->_ruleMap[$key])) {
            $key = $this->_ruleMap[$key];
            return isset($this->_options[$key]);
        }
        return false;
    }
public function __isset($key)
    {
        $this->parse();
        if (isset($this->_ruleMap[$key])) {
            $key = $this->_ruleMap[$key];
            return isset($this->_options[$key]);
        }
        return false;
    }
public function __isset ( $ key ) { $ this -> parse ( ) ; if ( isset ( $ this -> _ruleMap [ $ key ] ) ) { $ key = $ this -> _ruleMap [ $ key ] ; return isset ( $ this -> _options [ $ key ] ) ; } return false ; }
Test whether a given option has been seen.

@param  string $key
@return boolean
Test whether a given option has been seen .