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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 parse_time_indices(s):
 """Parse a string as time indices. Args: s: A valid slicing string for time indices. E.g., '-1', '[:]', ':', '2:10' Returns: A slice object. Raises: ValueError: If `s` does not represent valid time indices. """

  if not s.startswith('['):
    s = '[' + s + ']'
  parsed = command_parser._parse_slices(s)
  if len(parsed) != 1:
    raise ValueError(
        'Invalid number of slicing objects in time indices (%d)' % len(parsed))
  else:
    return parsed[0]