* These long-dead variants of the proto matchers don't exist in the current version of Googletest.
* No evidence of external usage: [the only external references I see](https://www.google.com/search?q=%22protocolmessageequals%22+OR+%22protocolmessageequals%22) are copies of this guide. Possibly they were already removed by the time Googletest was publicly released.
PiperOrigin-RevId: 565358401
Change-Id: I61379b7333fa8ee19cd5520caedf2c539f54c2d7
Michael Hirshleifer