code: func Contains(t TestingT, s, contains interface{}, msgAndArgs ...interface{}) bool {
  	if h, ok := t.(tHelper); ok {
  		h.Helper()
  	}
  
  	ok, found := includeElement(s, contains)
  	if !ok {
  		return Fail(t, fmt.Sprintf("\"%s\" could not be applied builtin len()", s), msgAndArgs...)
  	}
  	if !found {
  		return Fail(t, fmt.Sprintf("\"%s\" does not contain \"%s\"", s, contains), msgAndArgs...)
  	}
  
  	return true
  
  }
docs: // Contains asserts that the specified string, list(array, slice...) or map contains the
  // specified substring or element.
  //
  //    assert.Contains(t, "Hello World", "World")
  //    assert.Contains(t, ["Hello", "World"], "World")
  //    assert.Contains(t, {"Hello": "World"}, "Hello")