def METHOD_NAME():
    DP_DIM, PP_DIM, TP_DIM = 0, 1, 2
    DP_SIZE, PP_SIZE, TP_SIZE = 1, 2, 2
    RANK_TO_COORDINATE = {
        0: (0, 0, 0),
        1: (0, 0, 1),
        2: (0, 1, 0),
        3: (0, 1, 1),
    }
    TP_RANKS_IN_GROUP = {
        0: [0, 1],
        1: [0, 1],
        2: [2, 3],
        3: [2, 3],
    }
    PP_RANKS_IN_GROUP = {
        0: [0, 2],
        1: [1, 3],
        2: [0, 2],
        3: [1, 3],
    }
    DP_RANKS_IN_GROUP = {
        0: [0],
        1: [1],
        2: [2],
        3: [3],
    }
    pg_mesh = ProcessGroupMesh(DP_SIZE, PP_SIZE, TP_SIZE)
    rank = dist.get_rank()
    assert rank == pg_mesh.rank
    # check world size
    assert pg_mesh.size(TP_DIM) == 2
    assert pg_mesh.size(PP_DIM) == 2
    assert pg_mesh.size(DP_DIM) == 1
    # check coordinate
    assert pg_mesh.coordinate(TP_DIM) == RANK_TO_COORDINATE[rank][TP_DIM]
    assert pg_mesh.coordinate(PP_DIM) == RANK_TO_COORDINATE[rank][PP_DIM]
    assert pg_mesh.coordinate(DP_DIM) == RANK_TO_COORDINATE[rank][DP_DIM]
    # check ranks in group
    tp_group = pg_mesh.get_group_along_axis(TP_DIM)
    assert pg_mesh.get_ranks_in_group(tp_group) == TP_RANKS_IN_GROUP[rank]
    pp_group = pg_mesh.get_group_along_axis(PP_DIM)
    assert pg_mesh.get_ranks_in_group(pp_group) == PP_RANKS_IN_GROUP[rank]
    dp_group = pg_mesh.get_group_along_axis(DP_DIM)
    assert pg_mesh.get_ranks_in_group(dp_group) == DP_RANKS_IN_GROUP[rank]
    # check prev rank
    if RANK_TO_COORDINATE[rank][TP_DIM] != 0:
        prev_coord = RANK_TO_COORDINATE[rank][:TP_DIM] + (RANK_TO_COORDINATE[rank][TP_DIM] - 1,) + \
            RANK_TO_COORDINATE[rank][TP_DIM + 1:]
        prev_rank = TP_RANKS_IN_GROUP[rank][TP_RANKS_IN_GROUP[rank].index(rank) - 1]
        assert pg_mesh.ravel(prev_coord, pg_mesh.shape) == prev_rank
    if RANK_TO_COORDINATE[rank][PP_DIM] != 0:
        prev_coord = RANK_TO_COORDINATE[rank][:PP_DIM] + (RANK_TO_COORDINATE[rank][PP_DIM] - 1,) + \
            RANK_TO_COORDINATE[rank][PP_DIM + 1:]
        prev_rank = PP_RANKS_IN_GROUP[rank][PP_RANKS_IN_GROUP[rank].index(rank) - 1]
        assert pg_mesh.ravel(prev_coord, pg_mesh.shape) == prev_rank
    # check next rank
    if RANK_TO_COORDINATE[rank][TP_DIM] != TP_SIZE - 1:
        next_coord = RANK_TO_COORDINATE[rank][:TP_DIM] + (RANK_TO_COORDINATE[rank][TP_DIM] + 1,) + \
            RANK_TO_COORDINATE[rank][TP_DIM + 1:]
        next_rank = TP_RANKS_IN_GROUP[rank][TP_RANKS_IN_GROUP[rank].index(rank) + 1]
        assert pg_mesh.ravel(next_coord, pg_mesh.shape) == next_rank
    if RANK_TO_COORDINATE[rank][PP_DIM] != PP_SIZE - 1:
        next_coord = RANK_TO_COORDINATE[rank][:PP_DIM] + (RANK_TO_COORDINATE[rank][PP_DIM] + 1,) + \
            RANK_TO_COORDINATE[rank][PP_DIM + 1:]
        next_rank = PP_RANKS_IN_GROUP[rank][PP_RANKS_IN_GROUP[rank].index(rank) + 1]
        assert pg_mesh.ravel(next_coord, pg_mesh.shape) == next_rank