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