🐛 Change LightningLoggerBase to Logger (#973)

Co-authored-by: Jirka Borovec <6035284+Borda@users.noreply.github.com>

pl_bolts/callbacks/data_monitor.py

@@ -3,7 +3,7 @@
 import numpy as np
 import torch
 from pytorch_lightning import Callback, LightningModule, Trainer
-from pytorch_lightning.loggers import LightningLoggerBase, TensorBoardLogger, WandbLogger
+from pytorch_lightning.loggers import TensorBoardLogger, WandbLogger
 from pytorch_lightning.utilities import rank_zero_warn
 from pytorch_lightning.utilities.apply_func import apply_to_collection
 from torch import Tensor, nn
@@ -14,6 +14,11 @@
 from pl_bolts.utils.stability import under_review
 from pl_bolts.utils.warnings import warn_missing_pkg
 
+try:
+    from pytorch_lightning.loggers import Logger
+except ImportError:
+    from pytorch_lightning.loggers import LightningLoggerBase as Logger
+
 if _WANDB_AVAILABLE:
     import wandb
 else:  # pragma: no cover
@@ -96,7 +101,7 @@ def log_histogram(self, tensor: Tensor, name: str) -> None:
 
             logger.experiment.log(data={name: wandb.Histogram(tensor)}, commit=False)
 
-    def _is_logger_available(self, logger: LightningLoggerBase) -> bool:
+    def _is_logger_available(self, logger: Logger) -> bool:
         available = True
         if not logger:
             rank_zero_warn("Cannot log histograms because Trainer has no logger.")