use std::borrow::Cow;use std::fmt::{Debug, Display, Formatter}; /// An error that is further described in a message.#[derive(Debug)]pub struct Message(    /// The error message.    pub(crate) Cow<'static, str>,); /// Lifecycleimpl Message {    /// Create a new instance that displays the given `message`.    pub fn new(message: impl Into<Cow<'static, str>>) -> Self {        Message(message.into())    }} impl Display for Message {    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {        f.write_str(self.0.as_ref())    }} impl std::error::Error for Message {} impl From<String> for Message {    fn from(msg: String) -> Self {        Message::new(msg)    }} impl From<&'static str> for Message {    fn from(msg: &'static str) -> Self {        Message::new(msg)    }} /// Return a new statically allocated `message`.////// Use the [message!-macro](crate::message!) for convenient `format!`-like behavior.pub fn message(message: &'static str) -> Message {    Message::new(message)}