if promoted is None:
                    promoted_mask = self._effective_promoted()
                elif promoted:
                    promoted_mask = self.promoted
                else:
                    promoted_mask = BB_EMPTY

import time

import chess
import chess.pgn

PATH_TO_PGN = "/path/to/file.pgn"
# https://database.lichess.org/standard/lichess_db_standard_rated_2026-02.pgn.zst
# PATH_TO_PGN = "lichess_db_standard_rated_2013-01.pgn"
MAX_GAMES = 5000

games = []
with open(PATH_TO_PGN, "r") as f:
    while len(games) < MAX_GAMES:
        game = chess.pgn.read_game(f)
        if game is None:
            break
        games.append(game)

num_positions = 0
total_elapsed = 0
for game in games:
    board = game.board()
    for move in game.mainline_moves():
        board.push(move)

        t0 = time.perf_counter()
        board.board_fen()
        total_elapsed += time.perf_counter() - t0

        num_positions += 1

calls_per_s = num_positions / total_elapsed

print(f"games={len(games)} num_positions={num_positions}")
print(f"total_elapsed={total_elapsed:.3f}")
print(f"calls_per_s={calls_per_s:.2f}")