docstr: The count method should return a value of 0
  when nothing has been saved to the database.
docstr_tok: ["The","count","method","should","return","a","value","of","0","when","nothing","has","been","saved","to","the","database","."]
code: def test_count_returns_zero(self):
      """
      The count method should return a value of 0
      when nothing has been saved to the database.
      """
      self.assertEqual(self.adapter.count(), 0)
  
imports: from unittest import TestCase
  from chatterbot.storage import MongoDatabaseAdapter
  from chatterbot.conversation import Statement
label_desc: Use image node_id 1 for calling the MongoDatabaseAdapterTestCase obj's underlying member method code with example usage: obj.test_count_returns_zero() without return types