code: def test_dict_no_keys(self):
      row = MappedSequence(self.data)
  
      with self.assertRaises(KeyError):
          row.dict()
  
imports: import unittest
  from agate.mapped_sequence import MappedSequence
label_desc: Use image node_id 20 for calling the TestMappedSequence obj's underlying member method code with example usage: obj.test_dict_no_keys() without return types