src/Request.php
public function setEncoding($encoding)
    {
        if (in_array($encoding, ['identity', 'deflate', 'gzip'])) {
            $this->curlOptions[ CURLOPT_ENCODING ] = $encoding;
        } else {
            $this->curlOptions[ CURLOPT_ENCODING ] = '';
        }

        return $this;
    }
public function setEncoding($encoding)
    {
        if (in_array($encoding, ['identity', 'deflate', 'gzip'])) {
            $this->curlOptions[ CURLOPT_ENCODING ] = $encoding;
        } else {
            $this->curlOptions[ CURLOPT_ENCODING ] = '';
        }

        return $this;
    }
Request::setEncoding

Sets the contents of the "Accept-Encoding: " header. This enables decoding of the response.
Supported encodings are "identity", "deflate", and "gzip".
If an empty string, "", is set, a header containing all supported encoding types is sent.

@param string $encoding Supported encodings are "identity", "deflate", and "gzip".

@return static