fn pre(&self) -> &H {
		match *self {
			PrePostHeader::Same(ref h) => h,
			PrePostHeader::Different(ref h, _) => h,
		}
	}
// get a reference to the "pre-header" -- the header as it should be just after the runtime.
get a reference to the "pre-header" -- the header as it should be just after the runtime.
get a reference to the " pre - header " -- the header as it should be just after the runtime .
fn pre(&self) -> &H {
		match *self {
			PrePostHeader::Same(ref h) => h,
			PrePostHeader::Different(ref h, _) => h,
		}
	}
fn pre ( & self ) -> & H { match * self { PrePostHeader :: Same ( ref h ) => h , PrePostHeader :: Different ( ref h , _ ) => h , } }
get a reference to the "pre-header" -- the header as it should be just after the runtime.
get a reference to the " pre - header " -- the header as it should be just after the runtime .
&self
&self