Expected method instancemethod.__call__ not called

I am trying to modify an old test case using new code. I am getting an error

`mox3.mox.ExpectedMethodCallsError: Verify: Expected methods never called:
 0.  instancemethod.__call__(<IgnoreArg>, content=<IgnoreArg>, extra_md=  <IgnoreArg>, network_info=<IgnoreArg>) -> None

How do I know with this information that which method has not been called ? Also what has been called in its place. AFAIK the -> None would mean nothing has been called in its place I am open to using pdb or any other technique that would help.

TIA

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