public bool Contains <T>(T item, GList <T> inputList) => inputList != null && inputList.Count > 0 && inputList.IsValid && item != null?inputList.Contains(item) : (default);
public int IndexOf <T>(T item, GList <T> inputList) => inputList != null && inputList.Count > 0 && inputList.IsValid && item != null && inputList.Contains(item) ? inputList.IndexOf(item) : -1;
public bool IsValid <T1, T2>(GList <T1> input1, GList <T2> input2) => input1.IsValid && input2.IsValid && input1.Count == input2.Count;