docs: def print_pos(self, coordinates=None, pos=None):
          '''Print the chessboard'''
          if not pos:
              pos = self.pos
          self.graph = [list(map(self._transform, pos[i])) for i in self.pos_range]
          xaxis = ' '.join([chr(ASC_ONE + _) for _ in range(min(self.board_size, MAX_NUM))])
          if (self.board_size > MAX_NUM):
              xaxis += ' '
              xaxis += ' '.join([chr(ASC_A + _ - MAX_NUM) for _ in range(MAX_NUM, min(self.board_size, MAX_CAP))])
          if (self.board_size > MAX_CAP):
              xaxis += ' '
              xaxis += ' '.join([chr(ASC_a + _ - MAX_CAP) for _ in range(MAX_CAP, self.board_size)])
          print('  ', end='')
          print(xaxis)
          for i in range(self.board_size):
              out = '|'.join(self.graph[i])
              if i < MAX_NUM:
                  print(chr(i + ASC_ONE), end='')
              elif MAX_NUM <= i < MAX_CAP:
                  print(chr(i - MAX_NUM + ASC_A), end='')
              elif MAX_CAP <= i < MAX_LOW:
                  print(chr(i - MAX_CAP + ASC_a), end='')
              print('|', end='')
              #Colorful print
              if coordinates:
                  for j in range(self.board_size):
                      if (i, j) in coordinates:
                          new_print = cprint
                          params = {
                              'color': 'w',
                              'bcolor': 'r',
                          }
                      else:
                          new_print = print
                          params = {}
                      new_print(self._transform(pos[i][j]), end='', **params)
                      print('|', end='') 
                  else:
                      print()
              else:
                  print(out, end='')
                  print('|')