private CustomOpEnvironment(
final Context context, final OpEnvironment parent, final Collection<? extends OpInfo> infos) {
setContext(context);
this.parent = parent;
index = new OpIndex();
// NB: If this is not performant and/or dynamic enough, we could create/use
// a concatenating collection (see e.g. Guava's Iterables.concat method)
// that does not copy all the elements.
if (parent != null) index.addOps(parent.infos());
index.addOps(infos);
}
