code: def print_levels(self, session):
          
          lines = []
          for level in sorted(self.get_levels()):
              methods = sorted(
                  method.__name__ for method in self.get_level_methods(level)
              )
              lines.append("- {0}:".format(level))
              lines.append("\t{0}".format(", ".join(methods)))
          session.write_line("\n".join(lines))
docs: Lists available levels