public function crop($start, $length = null)
    {
        $this->setInternalValue(mb_substr($this->getInternalValue(), $start, $length, 'UTF-8'));

        return $this;
    }
public function crop($start, $length = null)
    {
        $this->setInternalValue(mb_substr($this->getInternalValue(), $start, $length, 'UTF-8'));

        return $this;
    }
public function crop ( $ start , $ length = null ) { $ this -> setInternalValue ( mb_substr ( $ this -> getInternalValue ( ) , $ start , $ length , 'UTF-8' ) ) ; return $ this ; }
Crop the current internal value

@param      $start
@param null $length

@return $this
Crop the current internal value