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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def step(self, action):
 """Forward action to the wrapped environment. Args: action: Action to apply to the environment. Raises: ValueError: Invalid action. Returns: Converted observation, converted reward, done flag, and info object. """

    observ, reward, done, info = self._env.step(action)
    observ = self._convert_observ(observ)
    reward = self._convert_reward(reward)
    return observ, reward, done, info