System.Linq.Expressions.CatchBlock.Update C# (CSharp) Метод

        public CatchBlock Update(ParameterExpression variable, Expression filter, Expression body)
        {
            if (variable == Variable && filter == Filter && body == Body)
            {
                return this;
            }
            return Expression.MakeCatchBlock(Test, variable, body, filter);
        }
    }

            protected override CatchBlock VisitCatchBlock(CatchBlock node)
            {
                if (node.Variable != null)
                {
                    _environment.Push(new[] { node.Variable });
                }

                //
                // Just visit children to perform inlining of constants or defaults. Note that the parent
                // try expression requires that non-trivial bindings are satisfied by the protected region
                // so we don't have to worry about that over here.
                //

                var filter = Visit(node.Filter);
                var body   = Visit(node.Body);

                if (node.Variable != null)
                {
                    _environment.Pop();
                }

                return(node.Update(node.Variable, filter, body));
            }