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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_assignable_bank_ids(self, bank_id):
 """Gets a list of bank including and under the given bank node in which any assessment part can be assigned. arg: bank_id (osid.id.Id):
 the ``Id`` of the ``Bank`` return: (osid.id.IdList) - list of assignable bank ``Ids`` raise: NullArgument - ``bank_id`` is ``null`` raise: OperationFailed - unable to complete request *compliance: mandatory -- This method must be implemented.* """

        # This will likely be overridden by an authorization adapter
        mgr = self._get_provider_manager('ASSESSMENT', local=True)
        lookup_session = mgr.get_bank_lookup_session(proxy=self._proxy)
        banks = lookup_session.get_banks()
        id_list = []
        for bank in banks:
            id_list.append(bank.get_id())
        return IdList(id_list)