public function subject($subject = null)
    {
        if ($subject !== null) {
            $this->_subject = $subject;

            return $this;
        }

        return $this->_subject;
    }
public function subject($subject = null)
    {
        if ($subject !== null) {
            $this->_subject = $subject;

            return $this;
        }

        return $this->_subject;
    }
public function subject ( $ subject = null ) { if ( $ subject !== null ) { $ this -> _subject = $ subject ; return $ this ; } return $ this -> _subject ; }
Gets or sets message's subject.

@param string $subject Subject
@return $this|string When new value is set, $this is returned for allowing
method chaining. When getting value a string will be returned
Gets or sets message s subject .