code: def get_changes(self, extracted_name, similar=False, global_=False):
          
          info = _ExtractInfo(
              self.project, self.resource, self.start_offset, self.end_offset,
              extracted_name, variable=self.kind == 'variable',
              similar=similar, make_global=global_)
          new_contents = _ExtractPerformer(info).extract()
          changes = ChangeSet('Extract %s <%s>' % (self.kind,
                                                   extracted_name))
          changes.add_change(ChangeContents(self.resource, new_contents))
          return changes
docs: Get the changes this refactoring makes
  
          :parameters:
              - `similar`: if `True`, similar expressions/statements are also
                replaced.
              - `global_`: if `True`, the extracted method/variable will
                be global.