code: def test_masking(self):
      # FEATURES.MD
      self.start_tests(name="masking")
  
      agent = Agent.create(
          agent=self.agent_spec(
              states=dict(type="float", shape=(10,)),
              actions=dict(type="int", shape=(), num_values=3),
          )
      )
  
      states = dict(
          state=np.random.random_sample(
              size=(10,)
          ),  # state (default name: "state")
          action_mask=[
              True,
              False,
              True,
          ],  # mask as'[ACTION-NAME]_mask' (default name: "action")
      )
      action = agent.act(states=states)
      assert action != 1
  
file_path: tensorforce/test/test_features.py
imports: import os
  from random import random
  from tempfile import TemporaryDirectory
  import unittest
  import numpy
  from tensorforce import Agent, Environment, Runner
  from test.unittest_base import UnittestBase
label_desc: Use image node_id 1 for calling the TestFeatures obj's underlying member method code with example usage: obj.test_masking() without return types