Per the Python SDK guidelines we shouldn't be importing implementations of HTTPTransport abstract classes. In azure-identity, we currently are explictly importing and using RequestsTransport and AioHttpTransport. See here.

The corresponding pylint check failure is:

azure/identity/_internal/pipeline.py:69: [C4750(non-abstract-transport-import), build_pipeline] Only import abstract transports.
azure/identity/_internal/pipeline.py:85: [C4750(non-abstract-transport-import), build_async_pipeline] Only import abstract transports.

The identity pipeline code should be refactored to use PipelineClients which will handle defaulting the transport if none is provided. Policies can also be passed to this client.