code: def test_learning_rate() -> None:
      assert_valid_param(
          param_name="learning_rate", param_values=[0.42, 17.8, 10.0]
      )
      assert_invalid_param(
          param_name="learning_rate",
          param_values=[-2, -1e-10, 0, float("inf"), float("nan")],
          exp_msg="The value of `learning_rate` should be > 0 (type=value_error)",
      )
  
file_path: gluonts/test/mx/trainer/test_trainer.py
imports: from typing import Any, List
  import pytest
  from gluonts.mx.trainer import Trainer
label_desc: Use image node_id 3 for calling a global function with example usage: test_learning_rate() without return types