presto-main/src/main/java/io/prestosql/sql/planner/plan/SimplePlanRewriter.java/RewriteContext/RewriteContext
class RewriteContext:        private RewriteContext(SimplePlanRewriter<C> nodeRewriter, C userContext)
        {
            this.nodeRewriter = nodeRewriter;
            this.userContext = userContext;
        }