class_docstr: Connect4 Board.
docstr: Create copy of board containing new stone.
docstr_tok: ["Create","copy","of","board","containing","new","stone","."]
code: def add_stone(self, column, player):
      "Create copy of board containing new stone."
      (available_idx,) = np.where(self.np_pieces[:, column] == 0)
      if len(available_idx) == 0:
          raise ValueError(
              "Can't play column %s on board %s" % (column, self)
          )
  
      self.np_pieces[available_idx[-1]][column] = player
  
imports: import numpy
  from collections import namedtuple
label_desc: Use image node_id 2 for calling the Board obj's underlying member method code with example usage: obj.add_stone(column, player) without return types