@abstractmethod on virtual methods

[david-waterworth]

There are a number of methods of the LightningDataModule which are marked as @abstractmethod even though they're not really abstract i.e. transfer_batch_to_device.

Requires that the metaclass is ABCMeta or derived from it. A
class that has a metaclass derived from ABCMeta cannot be
instantiated unless all of its abstract methods are overridden.
The abstract methods can be called using any of the normal
'super' call mechanisms. abstractmethod() may be used to declare
abstract methods for properties and descriptors.

The issue is the linter complains that my DataModule cannot be instantiated since I've not implemented transfer_batch_to_device and my IDE highlights my lightning modules red.

Is there any need for this decorator? It seems that transfer_batch_to_device is virtual, not abstract, and all python methods are virtual.

[rohitgr7]

this hook is already present in DataHooks so should not be there. Will update this in #3671.

[stale]

This issue has been automatically marked as stale because it hasn't had any recent activity. This issue will be closed in 7 days if no further activity occurs. Thank you for your contributions, Pytorch Lightning Team!