TensorRunningAccum does not reset as it assumed to be
🐛 Bug
I looked into the source code in this file and found this snippet that does not make sense to me.
    def reset(self) -> None:
        """Empty the accumulator."""
        self = TensorRunningAccum(self.window_length)
To Reproduce
I made a short code snippet to verify this behavior as follows.
from pytorch_lightning.trainer.supporters import TensorRunningAccum

running_accum = TensorRunningAccum(window_length=10)
running_accum.current_idx = 100     # just want to change the value
print(id(running_accum))
print(running_accum.current_idx)

running_accum.reset()
print(running_accum.current_idx)    # current_idx is expected to be 0
print(id(running_accum))
And the result is
139686191621984
100
100
139686191621984