code: def on_epoch_end(self, embeddings):
      self.epoch_event += 1
  
file_path: cuml/python/cuml/tests/test_internals_api.py
imports: import pytest
  from cuml.manifold import UMAP
  from cuml.internals import GraphBasedDimRedCallback
  from sklearn.datasets import load_digits
label_desc: Use image node_id 4 for calling the CustomCallback obj's underlying member method code with example usage: obj.on_epoch_end(embeddings) without return types