return bom;
}
@SuppressWarnings("unchecked")
public <T> Iterable<NamedComponent<T>> get(Factory.Query<T> key) {
ImmutableCollection namedComponents = checkNotNull(materials.get(key),
"key not found: %s. Check your bill of materials. Available keys: %s", key, materials.keySet());
return (Iterable<NamedComponent<T>>) namedComponents;
}