code: func (m *Mux) ExecuteRawString(src string, binding interface{}) (result string, err error) {
  	out := m.buffer.Get()
  	defer m.buffer.Put(out)
  	err = m.ExecuteRaw(src, out, binding)
  	if err == nil {
  		result = out.String()
  	}
  	return
  }
docs: // ExecuteRawString receives raw template source contents and returns it's result as string