OOP model callers need one predictable query view for schematics, boards, footprints, projects, and designs instead of ad hoc list traversal.
Provide a read-only live sequence with type/name filtering, exact-attribute filtering, count, first, and materialization helpers.
Tests must prove the collection is sequence-like, live, filterable by class and class name, and rejects direct mutation.
A model-owned collection facade is public when it supports common query helpers without owning or mutating the underlying model list.