docstr: Process the args into the x and y arrays.
  
  If only y is passed, x is set to None.
docstr_tok: ["Process","the","args","into","the","x","and","y","arrays",".","If","only","y","is","passed",",","x","is","set","to","None","."]
code: def _process_args(*args) -> Tuple[np.ndarray | None, np.ndarray]:
      """Process the args into the x and y arrays.
  
      If only y is passed, x is set to None.
      """
      assert len(args) in [1, 2], "Must pass either 1 or 2 arrays"
      x, y = (None, args[0]) if len(args) == 1 else args
      return x, y
  
imports: from __future__ import annotations
  import re
  from abc import ABC, abstractmethod
  from typing import List, Optional, Tuple
  import numpy
label_desc: Use image node_id 3 for calling the AbstractAggregator obj's underlying member method code with example usage: obj._process_args() and returns: x,  y