src/Http.php
public function progress($callback) {
        $this->setOption(CURLOPT_PROGRESSFUNCTION, $callback);
        $this->setOption(CURLOPT_NOPROGRESS, false);
        return $this;
    }
public function progress($callback) {
        $this->setOption(CURLOPT_PROGRESSFUNCTION, $callback);
        $this->setOption(CURLOPT_NOPROGRESS, false);
        return $this;
    }
Progress

@access public
@param  $callback
@return Http