Swift_Mime_ContentEncoder_NativeQpContentEncoder::charsetChanged PHP Method

    public function charsetChanged($charset)
    {
        $this->charset = $charset;
    }

 public function testCharsetChangeNotImplemented()
 {
     $this->_encoder->charsetChanged('utf-8');
     $this->expectException(new RuntimeException('Charset "charset" not supported. NativeQpContentEncoder only supports "utf-8"'));
     $this->_encoder->charsetChanged('charset');
     $this->_encoder->encodeString('foo');
 }