code: func (builder *SSMLTextBuilder) AppendSayAs(interpretAs, format, text string) *SSMLTextBuilder {
  
  	if interpretAs == "date" {
  		builder.buffer.WriteString(fmt.Sprintf("<say-as interpret-as=\"%s\" format=\"%s\">%s</say-as>",
  			interpretAs, format, text))
  	} else if interpretAs != "" {
  		builder.buffer.WriteString(fmt.Sprintf("<say-as interpret-as=\"%s\">%s</say-as>", interpretAs, text))
  	}
  
  	return builder
  }
docs: // AppendSayAs is used to provide additional information about how the text string being appended
  // should be interpreted. For example this can be used to interpret the string as a list
  // of individual characters or to read out digits one at a time. The format string is
  // ignored unless the interpret-as argument is `date`. Refer to the SSML referene for valid
  // values for the interpretAs parameter.