Support for passing dataloader to trainer.test()
🚀 Feature
dl = DataLoader(...)
trainer = Trainer(...)
trainer.test(model, dl)
Motivation
In most cases of mine, I got a fixed training/validation dataset but other collaborators would send me different datasets to evaluate my model. In which case, I hope not to modify the code inside the CoolSystem.  I prefer to build different dataloaders for different collaborators in an evaluation.py, which sounds more reasonable than putting unseen test data into the training process.
I found there are similar features in trainer.fit(). I am wondering if it is possible to have this feature for trainer.test().
Current Solution
My current solution follows a complex way but wish to have a feature to simplify it.
class MyCoolSystem(pl.lightning_module):
    ...
class CoolSystemForDataA(MyCoolSystem):
    def test_dataloader():
          # Overriden dataloaders.