def METHOD_NAME(state, fork_epoch, spec, post_spec, pre_tag, post_tag):
    """
    Create an attester slashing right *before* the transition
    """
    yield from run_transition_with_operation(
        state,
        fork_epoch,
        spec,
        post_spec,
        pre_tag,
        post_tag,
        operation_type=OperationType.PROPOSER_SLASHING,
        operation_at_slot=fork_epoch * spec.SLOTS_PER_EPOCH - 1,
    )