title: When we use the google protocol buffer, could we modify the generated pb.go file?
body: <p>For example, is it ok to add an interface or associate a function I created with a struct in the generated pb.go file?</p>
  
  <p>The reason that I want to make these kinds of changes is it would make my code easier to implement. I am not sure if I am allowed to do this since the first commented line in the generated file says "DO NOT EDIT".</p>