public function read($len = null)
    {
        if (!$this->getInitialized()) {
            $this->initialize();
            $this->setInitialized(true);
        }

        while (($buffer = $this->in->read($len)) !== -1) {
            // Remove the last "\n" from buffer for
            // prevent explode to add an empty cell at
            // the end of array
            $buffer = trim($buffer, "\n");

            $lines = explode("\n", $buffer);
            $skip = $this->skip > 0 ? $this->skip : 0;

            if (count($lines) >= $this->lines) {
                // Buffer have more (or same) number of lines than needed.
                // Fill lineBuffer with the last "$this->_lines" lasts ones.
                $off = count($lines) - $this->lines;
                if ($skip > 0) {
                    $this->lineBuffer = array_slice($lines, $off - $skip, -$skip);
                } else {
                    $this->lineBuffer = array_slice($lines, $off);
                }
            } else {
                // Some new lines ...
                // Prepare space for insert these new ones
                $this->lineBuffer = array_slice($this->lineBuffer, count($lines) - 1);
                $this->lineBuffer = array_merge($this->lineBuffer, $lines);
            }
        }

        if (empty($this->lineBuffer)) {
            $ret = -1;
        } else {
            $ret = implode("\n", $this->lineBuffer);
            $this->lineBuffer = [];
        }

        return $ret;
    }