code: def call_and_catch_errors(self, f, *args, **kwargs):
          
          try:
              return f(*args, **kwargs)
          except SassError as e:
              if self.live_errors:
                  # TODO should this setting also capture and display warnings?
                  return e.to_css()
              else:
                  raise
docs: Call the given function with the given arguments.  If it succeeds,
          return its return value.  If it raises a :class:`scss.errors.SassError`
          and `live_errors` is turned on, return CSS containing a traceback and
          error message.