interface IA { T Method (int index); } interface IB { void Method (int index); } interface IC : IA, IB { void Method (params int[] index); } class M : IC { void IC.Method (params int[] index) { } string IA.Method (int index) { throw new System.NotImplementedException (); } void IB.Method (int index) { throw new System.NotImplementedException (); } public static void Main () { IC ic = new M (); ic.Method (1); } }