code: def test_masking(self):
      self.start_tests(name="masking")
  
      agent, environment = self.prepare(
          states=dict(
              type="float", shape=(10,), min_value=-1.0, max_value=2.0
          ),
          actions=dict(type="int", shape=(), num_values=3),
      )
      states = environment.reset()
      assert "state" in states and "action_mask" in states
      states["action_mask"] = [True, False, True]
  
      action = agent.act(states=states)
      assert action != 1
  
      agent.close()
      environment.close()
      self.finished_test()
  
file_path: tensorforce/test/test_documentation.py
imports: import unittest
  from tensorforce import Agent, Environment, Runner
  from test.unittest_base import UnittestBase
label_desc: Use image node_id 6 for calling the TestDocumentation obj's underlying member method code with example usage: obj.test_masking() without return types