http/httpheader.go
func (s *HttpHeader) GetReader(h http.Header) *HttpHeader {
	s.Value = h.Get(s.Name)
	return s
}
func (s *HttpHeader) GetReader(h http.Header) *HttpHeader {
	s.Value = h.Get(s.Name)
	return s
}
// GetReader gets HTTP header value, as defined by current instance, from
// Request Header and sets to current instance.