thrift/context.go
func WithHeaders(ctx context.Context, headers map[string]string) Context {
	return tchannel.WrapWithHeaders(ctx, headers)
}
func WithHeaders(ctx context.Context, headers map[string]string) Context {
	return tchannel.WrapWithHeaders(ctx, headers)
}
// WithHeaders returns a Context that can be used to make a call with request headers.