In older Pharo versions it was possible to compare two methods selecting them via UI. 

I couldn't find this opportunity in Pharo10,  so digging into the source code I found SpDiffPresenter, if you pass to it a couple of selectors it can compare them.

Example:

SpDiffPresenter new

showOptions: true;

leftText: (MyObject >> #firstSelector) sourceCode;

rightText: (MyObject >> #secondSelector) sourceCode;

contextClass: True;

open 

Cheers

Davide