code: def testManualNodeConstruction(self):
      node = manual_node.ManualNode(description="test_description")
      self.assertDictEqual(
          node.exec_properties,
          {
              manual_node.DESCRIPTION_KEY: "test_description",
          },
      )
      self.assertEmpty(node.inputs)
      self.assertEmpty(node.outputs)
  
imports: import tensorflow
  from tfx.dsl.components.common import manual_node
label_desc: Use image node_id 1 for calling the ManualNodeTest obj's underlying member method code with example usage: obj.testManualNodeConstruction() without return types