code: def walk(self, *types):
          '''
          Iterator which visits all suites and suite files,
          yielding test cases and keywords
          '''
          requested = types if len(types) > 0 else [SuiteFile, ResourceFile, SuiteFolder, Testcase, Keyword]
  
          for thing in self.robot_files:
              if thing.__class__ in requested:
                  yield thing
              if isinstance(thing, SuiteFolder):
                  for child in thing.walk():
                      if child.__class__ in requested:
                          yield child
              else:
                  for child in thing.walk(*types):
                      yield chilf walk(self, *types):
          '''
          Iterator which visits all suites and suite files,
          yielding test cases and keywords
          '''
          requested = types if len(types) > 0 else [SuiteFile, ResourceFile, SuiteFolder, Testcase, Keyword]
  
          for thing in self.robot_files:
              if thing.__class__ in requested:
                  yield thing
              if isinstance(thing, SuiteFolder):
                  for child in thing.walk():
                      if child.__class__ in requested:
                          yield child
              else:
                  for child in thing.walk(*types):
                      yield child
docs: Iterator which visits all suites and suite files,
          yielding test cases and keywords