public static bool Equals(ILocalSymbol x, ILocalSymbol y)
        {
            if (ReferenceEquals(x, y))
            {
                return(true);
            }

            if (x == null ||
                y == null)
            {
                return(false);
            }

            return(x.MetadataName == y.MetadataName &&
                   SymbolComparer.Equals(x.ContainingSymbol, y.ContainingSymbol));
        }