class_docstr: Connect4 Game class implementing the alpha-zero-general Game interface.
  
  Use 1 for player1 and -1 for player2.
docstr: Input:
      board: current board
  
  Returns:
      boardString: a quick conversion of board to a string format.
                   Required by MCTS for hashing.
docstr_tok: ["Input",":","board",":","current","board","Returns",":","boardString",":","a","quick","conversion","of","board","to","a","string","format",".","Required","by","MCTS","for","hashing","."]
code: def stringRepresentation(self, board):
      """
      Input:
          board: current board
  
      Returns:
          boardString: a quick conversion of board to a string format.
                       Required by MCTS for hashing.
      """
      return board.tobytes()
  
imports: import numpy
  from collections import namedtuple
label_desc: Use image node_id 10 for calling the Connect4Game obj's underlying member method code with example usage: obj.stringRepresentation(board) and returns: board