modules that own those concepts
No behavior change. `Runner` had grown four private helpers that parse node
paths, classify branches and scan events, none of which depend on runner state:
- `_strip_run_ids_from_path` -> `_NodePathBuilder.static_path`. Node paths are
`/`-separated and owned by `_NodePathBuilder`, which already strips the run id
off the leaf segment; this generalises that to every segment instead of
reimplementing the parsing in `Runner`.
- `_is_tool_branch` -> `_BranchPath.is_tool_branch`. Branches are
`.`-separated and owned by `_BranchPath`, which the helper already depended on.
- `_collect_function_call_ids` -> `_collect_function_call_ids` in
`flows/llm_flows/functions`, next to `find_event_by_function_call_id`.
- `_find_static_node_path` -> `find_static_node_path` in `workflow/_base_node`,
the module that defines the node tree it walks.
Keeping the two path types with their own classes also removes a hazard: node
paths and branches both look like `name@id` segments but use different
separators, so parsing them by hand in a third module invites applying the wrong
one.
Co-authored-by: Shangjie Chen <deanchen@google.com>
PiperOrigin-RevId: 970192989
Shangjie Chen
646c97645c