Bug for signed source-target search

[kkaris]

Query:

• source: PF-00477736
• target: DNM1L
• sign: + or -

Error log:

[2024-05-21 17:49:20 +0000] [7] [ERROR] Exception in ASGI application
Traceback (most recent call last):
  File "/sw/indra_network_search/indra_network_search/result_handler.py", line 344, in _check_source_and_target
    assert isinstance(self.source, Node)
AssertionError

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/local/lib/python3.8/dist-packages/uvicorn/protocols/http/h11_impl.py", line 407, in run_asgi
    result = await app(  # type: ignore[func-returns-value]
  File "/usr/local/lib/python3.8/dist-packages/uvicorn/middleware/proxy_headers.py", line 69, in __call__
    return await self.app(scope, receive, send)
  File "/usr/local/lib/python3.8/dist-packages/fastapi/applications.py", line 290, in __call__
    await super().__call__(scope, receive, send)
  File "/usr/local/lib/python3.8/dist-packages/starlette/applications.py", line 122, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/usr/local/lib/python3.8/dist-packages/starlette/middleware/errors.py", line 184, in __call__
    raise exc
  File "/usr/local/lib/python3.8/dist-packages/starlette/middleware/errors.py", line 162, in __call__
    await self.app(scope, receive, _send)
  File "/usr/local/lib/python3.8/dist-packages/starlette/middleware/cors.py", line 91, in __call__
    await self.simple_response(scope, receive, send, request_headers=headers)
  File "/usr/local/lib/python3.8/dist-packages/starlette/middleware/cors.py", line 146, in simple_response
    await self.app(scope, receive, send)
  File "/usr/local/lib/python3.8/dist-packages/starlette/middleware/exceptions.py", line 79, in __call__
    raise exc
  File "/usr/local/lib/python3.8/dist-packages/starlette/middleware/exceptions.py", line 68, in __call__
    await self.app(scope, receive, sender)
  File "/usr/local/lib/python3.8/dist-packages/fastapi/middleware/asyncexitstack.py", line 20, in __call__
    raise e
  File "/usr/local/lib/python3.8/dist-packages/fastapi/middleware/asyncexitstack.py", line 17, in __call__
    await self.app(scope, receive, send)
  File "/usr/local/lib/python3.8/dist-packages/starlette/routing.py", line 718, in __call__
    await route.handle(scope, receive, send)
  File "/usr/local/lib/python3.8/dist-packages/starlette/routing.py", line 276, in handle
    await self.app(scope, receive, send)
  File "/usr/local/lib/python3.8/dist-packages/starlette/routing.py", line 66, in app
    response = await func(request)
  File "/usr/local/lib/python3.8/dist-packages/fastapi/routing.py", line 241, in app
    raw_response = await run_endpoint_function(
  File "/usr/local/lib/python3.8/dist-packages/fastapi/routing.py", line 169, in run_endpoint_function
    return await run_in_threadpool(dependant.call, **values)
  File "/usr/local/lib/python3.8/dist-packages/starlette/concurrency.py", line 41, in run_in_threadpool
    return await anyio.to_thread.run_sync(func, *args)
  File "/usr/local/lib/python3.8/dist-packages/anyio/to_thread.py", line 56, in run_sync
    return await get_async_backend().run_sync_in_worker_thread(
  File "/usr/local/lib/python3.8/dist-packages/anyio/_backends/_asyncio.py", line 2144, in run_sync_in_worker_thread
    return await future
  File "/usr/local/lib/python3.8/dist-packages/anyio/_backends/_asyncio.py", line 851, in run
    result = context.run(func, *args)
  File "/sw/indra_network_search/indra_network_search/rest_api.py", line 246, in query
    results = network_search_api.handle_query(rest_query=search_query)
  File "/sw/indra_network_search/indra_network_search/search_api.py", line 91, in handle_query
    result_managers[alg_name] = self.shared_parents(query)
  File "/sw/indra_network_search/indra_network_search/search_api.py", line 323, in shared_parents
    return OntologyResultManager(path_generator=path_gen, graph=graph, **oq.result_options())
  File "/sw/indra_network_search/indra_network_search/result_handler.py", line 776, in __init__
    super().__init__(
  File "/sw/indra_network_search/indra_network_search/result_handler.py", line 310, in __init__
    self._check_source_target()
  File "/sw/indra_network_search/indra_network_search/result_handler.py", line 787, in _check_source_target
    self._check_source_and_target()
  File "/sw/indra_network_search/indra_network_search/result_handler.py", line 347, in _check_source_and_target
    raise ValueError(
ValueError: Both source and target must be provided and be instance of Node for shared_parents