class_docstr: Connect4 Board.
docstr: Set up initial board configuration.
docstr_tok: ["Set","up","initial","board","configuration","."]
code: def __init__(
      self, height=None, width=None, win_length=None, np_pieces=None
  ):
      "Set up initial board configuration."
      self.height = height or DEFAULT_HEIGHT
      self.width = width or DEFAULT_WIDTH
      self.win_length = win_length or DEFAULT_WIN_LENGTH
  
      if np_pieces is None:
          self.np_pieces = np.zeros(
              [self.height, self.width], dtype=np.int32
          )
      else:
          self.np_pieces = np_pieces
          assert self.np_pieces.shape == (self.height, self.width)
  
imports: import numpy
  from collections import namedtuple
label_desc: Use image node_id 1 to create a new Board object  with example: obj = Board(height, width, win_length, np_pieces)