}
	}
	for k := range opts.Header {
		if strings.HasPrefix(k, ":") {
			return fmt.Errorf("promised request headers cannot include pseudo header %q", k)
		}
		// These headers are meaningful only if the request has a body,
		// but PUSH_PROMISE requests cannot have a body.
		// http://tools.ietf.org/html/rfc7540#section-8.2
		// Also disallow Host, since the promised URL must be absolute.