private string DeclareExplicitVariant(VBAParser.ConstSubStmtContext context, out string instruction)
        {
            if (context == null)
            {
                instruction = null;
                return null;
            }

            var parent = (VBAParser.ConstStmtContext) context.Parent;
            instruction = parent.GetText();

            var constant = context.GetText();
            var replacement = context.ambiguousIdentifier().GetText() + ' '
                         + Tokens.As + ' ' + Tokens.Variant + ' '
                         + context.EQ().GetText() + ' '
                         + context.valueStmt().GetText();

            var result = instruction.Replace(constant, replacement);
            return result;
        }