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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 _reset(self, indices):
 """Resets environments at indices shouldn't pre-process or record. Subclasses should override this to do the actual reset if something other than the default implementation is desired. Args: indices: list of indices of underlying envs to call reset on. Returns: np.ndarray of stacked observations from the reset-ed envs. """


    # Pre-conditions: common_preconditions, see `assert_common_preconditions`.
    self.assert_common_preconditions()

    # This returns a numpy array with first dimension `len(indices)` and the
    # rest being the dimensionality of the observation.
    return np.stack([self._envs[index].reset() for index in indices])