code: def test_calculate_project_files_hash(self):
      self.project_controller.init("test7", "test description")
  
      filepath1, dirpath1 = self.__setup()
  
      # Test if hash is for 1 blank filepath and empty directory
      result = (
          self.file_collection_controller._calculate_project_files_hash()
      )
      assert result == "74be16979710d4c4e7c6647856088456"
  
imports: import os
  import shutil
  import tempfile
  import platform
  from io import open
  from datmo.config import Config
  from datmo.core.controller.project import ProjectController
  from datmo.core.controller.file.file_collection import FileCollectionController
  from datmo.core.util.exceptions import EntityNotFound, UnstagedChanges
label_desc: Use image node_id 9 for calling the TestFileCollectionController obj's underlying member method code with example usage: obj.test_calculate_project_files_hash() without return types