def _AddDataTableSeries(channel_data, output_data):
  """Adds series to the DataTable inputs.

  Args:
    channel_data: A dictionary of channel names to their data.  Each value in
    the dictionary has the same sampling frequency and the same time slice.
    output_data: Current graph data for DataTable API.
  Returns:
    The edited output_data dictionary where the first index represents the
    time axis value and the second the series value.
  """
  for i in range(len(list(channel_data.values())[0])):
    output_data[i].update({channel_name: data[i]
                           for channel_name, data in channel_data.items()})
  return output_data