// Also set mReturnType; if this referenced a UniversalType, use the resolved
// version. Otherwise, use the version from the function directly.
Type fnRetType = mFnSymbol.getReturnType();
try {
mReturnType = fnRetType.replaceUniversal(unificationOut);
} catch (TypeCheckException tce) {
// We can only resolve against our arguments, not our caller's type.
if (fnRetType instanceof ListType) {
// If the unresolved typevar is an argument to a list type, we can
// return this -- it's going to be an empty list, so we can return