src/Util/Utf8String.php
public function reduce($start, $length = null)
    {
        $this->_string = \mb_substr($this->_string, $start, $length);

        return $this;
    }
public function reduce($start, $length = null)
    {
        $this->_string = \mb_substr($this->_string, $start, $length);

        return $this;
    }
public function reduce ( $ start , $ length = null ) { $ this -> _string = \ mb_substr ( $ this -> _string , $ start , $ length ) ; return $ this ; }
Reduce the strings.

@param   int $start  Position of first character.
@param   int $length Maximum number of characters.

@return  self
Reduce the strings .