Return True if all methods in this group are called at least once.

def IsSatisfied(self):
    """Return True if all methods in this group are called at least once."""
    # NOTE(psycho): We can't use the simple set difference here because we want
    # to match different parameters which are considered the same e.g. IsA(str)
    # and some string. This solution is O(n^2) but n should be small.
    tmp = self._methods.copy()
    for called in self._methods_called:
      for expected in tmp:
        if called == expected:
          tmp.remove(expected)
          if not tmp:
            return True
          break
    return False