The type of an item comparer
Implementations of this interface must asure that the method is self-consistent
and defines a sorting order on items, or state precise conditions under which this is true.Implementations must assure that repeated calls of
the method to the same (in reference or binary identity sense) arguments
will return values with the same sign (-1, 0 or +1), or state precise conditions
under which the user
can be assured repeated calls will return the same sign.Implementations of this interface must always return values from the method
and never throw exceptions.This interface is identical to System.Collections.Generic.IComparer<T>