A string value is a (possibly empty) sequence of bytes.
The number of bytes is called the length of the string and is never negative.
Strings are immutable: once created,
it is impossible to change the contents of a string.
The predeclared string type is <code>string</code>;
it is a <a href="#Type_definitions">defined type</a>.
</p>

<p>
The length of a string <code>s</code> can be discovered using

	trailers, err := http2commaSeparatedTrailers(req)
	if err != nil {
		return err
	}
	hasTrailers := trailers != ""
	contentLen := http2actualContentLength(req)
	hasBody := contentLen != 0
	hdrs, err := cc.encodeHeaders(req, cs.requestedGzip, trailers, contentLen)
	if err != nil {
		return err
	}

	// Write the request.
	endStream := !hasBody && !hasTrailers
	cs.sentHeaders = true