code: def test_forward_flags_are_updated(self):
      input_type = PandasDataframe(
          columns=["Frame_Array"],
          column_types=[NdArrayType.UINT8],
          column_shapes=[(3, 256, 256)],
      )
      output_type = NumpyArray(
          name="label",
          type=NdArrayType.STR,
      )
  
      @forward(
          input_signatures=[input_type], output_signatures=[output_type]
      )
      def forward_func():
          pass
  
      forward_func()
      self.assertEqual(forward_func.tags["input"], [input_type])
      self.assertEqual(forward_func.tags["output"], [output_type])
  
file_path: evadb/test/unit_tests/functions/decorators/test_decorators.py
imports: import unittest
  from evadb.catalog.catalog_type import NdArrayType
  from evadb.functions.decorators.decorators import forward, setup
  from evadb.functions.decorators.io_descriptors.data_types import NumpyArray, PandasDataframe
label_desc: Use image node_id 3 for calling the DecoratorTests obj's underlying member method code with example usage: obj.test_forward_flags_are_updated() without return types