class_docstr: Tests for ``FolderMapView``
class_docstr_tok: ["Tests","for","``","FolderMapView","``"]
docstr: Test that the ``len()`` method returns the number of
  publicly visible keys only.
docstr_tok: ["Test","that","the","``","len","(",")","``","method","returns","the","number","of","publicly","visible","keys","only","."]
code: def test_len(self, init, len_):
      """Test that the ``len()`` method returns the number of
      publicly visible keys only."""
  
      assert len(FolderMapView(init)) == len_
  
file_path: pennylane/tests/data/data_manager/test_foldermap.py
imports: import re
  import pytest
  from pennylane.data.data_manager import DEFAULT, FULL, DataPath
  from pennylane.data.data_manager.foldermap import Description, FolderMapView
label_desc: Use image node_id 11 for calling the TestFolderMapView obj's underlying member method code with example usage: obj.test_len(init, len_) without return types