message: feat(body): add `Body::is_empty()` method
diff: @@ -49,6 +49,22 @@ impl Body {
  let (tx, rx) = channel();
  (tx.tx, rx)
  }
  +
  + /// Returns if this body was constructed via `Body::empty()`.
  + ///
  + /// # Note
  + ///
  + /// This does **not** detect if the body stream may be at the end, or
  + /// if the stream will not yield any chunks, in all cases. For instance,
  + /// a streaming body using `chunked` encoding is not able to tell if
  + /// there are more chunks immediately.
  + #[inline]
  + pub fn is_empty(&self) -> bool {
  + match self.0 {
  + Inner::Empty => true,
  + _ => false,
  + }
  + }
  }
  impl Default for Body {
  