neutral_ex_case_a.ts

// Top-level module:
const wellKnownTypes = [ ... ];  // Top-level var with more than one "Type".
const dataType = ...;

function ForwardDeclareClasses(topics: ReadonlyArray<TypedTopic>): ClassMap {
  const classes = new Map<string, Class>();
  for (const wk of wellKnownTypes) {
    classes.set(wk.subject.toString(), wk);
  }
  classes.set(dataType.subject.toString(), wk);
  for (const topic of topics) {
    // ...
  }

  if (classes.size === 0) {
    throw new Error('Expected Class topics to exist.');
  }

  return classes;
}