private signature module MySig {

predicate foo();

}

private module MyImpl implements MySig {

predicate foo() { none() }

}

private module MkThing<MySig Impl> {

signature module SubMod {

predicate bar();

}

}

module SimpleMod { }

import SimpleMod

private module SecondImpl implements MkThing<MyImpl>::SubMod {

predicate bar() { none() }

}

class Node extends int {

Node() { this = [0 .. 10] }

}

predicate sccEdge(Node a, Node b) { a = b % 2 }

private module Scc = QlBuiltins::EquivalenceRelation<Node, sccEdge/2>;

private class TypeFlowScc = Scc::EquivalenceClass;

/** Holds if `n` is part of an SCC of size 2 or more represented by `scc`. */

predicate sccRepr(Node n, TypeFlowScc scc) { scc = Scc::getEquivalenceClass(n) }

predicate sccJoinStep(Node n, TypeFlowScc scc) { none() }

module NewEntity {

newtype TFoo = TFoo1()

newtype EntityKey =

Key1() or

Key2()

// this errors out in normal QL, but QL-for-QL doesn't differentiate between upgrade scripts and "normal" code, and it also doesn't care if the number of type-parameters matches.

// so this should work fine in QL-for-QL

module NewEntityModule = QlBuiltins::NewEntity<EntityKey>;

class Union = TFoo or NewEntityModule::EntityId;

class Foo extends Union {

string toString() { none() }

}

predicate foo(Foo id, string message) {

id = NewEntityModule::map(Key1()) and message = "upgrade-1"

or

id = NewEntityModule::map(Key2()) and message = "upgrade-2"

}

}