public function lock($locked = true)
    {
        $this->_locked = $locked === false ? false : true;
        return $this;
    }
public function lock($locked = true)
    {
        $this->_locked = $locked === false ? false : true;
        return $this;
    }
public function lock ( $ locked = true ) { $ this -> _locked = $ locked === false ? false : true ; return $ this ; }
Sets the schema lock type. When Locked all extra fields which
are not part of the schema should be filtered out before saving.

@param  boolean $locked The locked value to set.
@return self            Return `$this`.
Sets the schema lock type . When Locked all extra fields which are not part of the schema should be filtered out before saving .