text: import numpy as np
  from absl import flags
  from gym.envs.registration import register
  from .pendulum import PendulumEnv 
  from .double_integrator import DoubleIntegratorEnv 
  FLAGS = flags.FLAGS
  
  register(
      id='DoubleIntegrator-v1',
      entry_point='envs:DoubleIntegratorEnv',
      max_episode_steps=200,
      kwargs={'max_acc': np.inf, 'init_y': 5., 'init_v': 3.},
  )
  
  register(
      id='PendulumBalance-v1',
      entry_point='envs:PendulumEnv',
      max_episode_steps=200,
      kwargs={'init_theta': 0.2, 'init_thetadot': 0.0, 'max_torque': 1.0, 'noise': FLAGS.pendulum_noise}
  )
  
  register(
      id='PendulumInvert-v1',
      entry_point='envs:PendulumEnv',
      max_episode_steps=200,
      kwargs={'init_theta': np.pi, 'init_thetadot': 0.0, 'max_torque': 1.0, 'noise': 0.0}
  )
  