code: func NotSubsetf(t TestingT, list interface{}, subset interface{}, msg string, args ...interface{}) bool {
  	if h, ok := t.(tHelper); ok {
  		h.Helper()
  	}
  	return NotSubset(t, list, subset, append([]interface{}{msg}, args...)...)
  }
docs: // NotSubsetf asserts that the specified list(array, slice...) contains not all
  // elements given in the specified subset(array, slice...).
  //
  //    assert.NotSubsetf(t, [1, 3, 4], [1, 2], "But [1, 3, 4] does not contain [1, 2]", "error message %s", "formatted")