code: func (m NiceMD) Get(key string) string {
  	k, _ := encodeKeyValue(key, "")
  	vv, ok := m[k]
  	if !ok {
  		return ""
  	}
  	return vv[0]
  }
docs: // Get retrieves a single value from the metadata.
  //
  // It works analogously to http.Header.Get, returning the first value if there are many set. If the value is not set,
  // an empty string is returned.
  //
  // The function is binary-key safe.