//// Copyright (c) 2007, Brian Frank and Andy Frank// Licensed under the Academic Free License version 3.0//// History:// 2 Feb 07 Brian Frank Creation//**** NotImmutableErr indicates using a mutable Obj where an immutable Obj is** required. See Obj.isImmutable for the definition of immutability.**const class NotImmutableErr : Err {**** Construct with specified error message and optional root cause.**new make(Str msg := "", Err? cause := null) }