class_docstr: A very simple Recipe for smoke test that runs one epoch and one iteration
  with only 1 random sample.
code: def search_space(self):
      return {
          "model": "MTNet",
          "lr": 0.001,
          "batch_size": 16,
          "epochs": 1,
          "cnn_dropout": 0.2,
          "rnn_dropout": 0.2,
          "time_step": hp.choice([3, 4]),
          "cnn_height": 2,
          "long_num": hp.choice([3, 4]),
          "ar_size": hp.choice([2, 3]),
          "past_seq_len": hp.sample_from(
              lambda spec: (spec.config.long_num + 1)
              * spec.config.time_step
          ),
      }
  
imports: from bigdl.chronos.autots.deprecated.config.base import Recipe
  from bigdl.orca.automl import hp
  from bigdl.chronos.utils import deprecated
label_desc: Use image node_id 2 for calling the MTNetSmokeRecipe obj's underlying member method code with example usage: obj.search_space() and returns: dict