code: def testUnnest_EmptyChannel_ReturnsEmptyList(self):
      input_dict = {"x": []}
  
      result = self._unnest(input_dict, key="x")
  
      self.assertEmpty(result)
  
file_path: tfx/tfx/dsl/input_resolution/ops/unnest_op_test.py
imports: import tensorflow
  from tfx.dsl.input_resolution import resolver_function
  from tfx.dsl.input_resolution import resolver_op
  from tfx.dsl.input_resolution.ops import ops
  from tfx.dsl.input_resolution.ops import test_utils
  from tfx.orchestration.portable.input_resolution import exceptions
label_desc: Use image node_id 7 for calling the UnnestOpTest obj's underlying member method code with example usage: obj.testUnnest_EmptyChannel_ReturnsEmptyList() without return types