code: def _default_distance_multi(
      x_values: np.ndarray, y_values: np.ndarray
  ):
      return np.sum(np.abs(x_values - y_values))
  
imports: import copy
  from typing import Callable, Optional, Union
  import numpy
  import pandas
  import xarray
  from darts import TimeSeries
  from darts.logging import get_logger, raise_if, raise_if_not
  from darts.timeseries import DIMS
  from .cost_matrix import CostMatrix
  from .window import CRWindow, NoWindow, Window
label_desc: Use image node_id 6 for calling a global function with example usage: _default_distance_multi(x_values, y_values) and returns: np