cannot import name 'ModelMetaclass' from 'pydantic.main

[shinkwee]

I found I cannot import he nis2pyr to python.
I use the following command line and received a import error.
from nis2pyr.convertor import convert_nd2_to_pyramidal_ome_tiff
The issue seems to be the authors of pydantic made ModelMetaclass private in recent version.

File ~/anaconda3/envs/nis2pyr/lib/python3.8/site-packages/nis2pyr/convertor.py:3
1 import nd2
2 from typing import Optional
----> 3 from nis2pyr.writer import write_pyramidal_ome_tiff
6 def convert_nd2_to_pyramidal_ome_tiff(nd2_filename: str,
7 pyramid_filename: str,
8 compression: Optional[str] = None,
9 tile_size: int = 256,
10 max_levels: int = 6) -> None:
11 """Convert an ND2 file to a tiled pyramidal OME TIFF file.
12
13 Args:
(...)
23 including the full resolution original.
24 """

File ~/anaconda3/envs/nis2pyr/lib/python3.8/site-packages/nis2pyr/writer.py:8
4 import tifffile # https://github.com/cgohlke/tifffile
6 from typing import Optional, Tuple
----> 8 from nis2pyr.metadata import update_channels_info, get_ome_voxelsize
9 from nis2pyr.reader import read_nd2file
10 from nis2pyr import version

File ~/anaconda3/envs/nis2pyr/lib/python3.8/site-packages/nis2pyr/metadata.py:1
----> 1 import ome_types
2 import tifffile
3 from typing import Any, Dict, List, Optional, Tuple

File ~/anaconda3/envs/nis2pyr/lib/python3.8/site-packages/ome_types/init.py:9
6 version = "unknown"
8 try:
----> 9 from . import model
10 from .model import OME
11 except ModuleNotFoundError as e:

File ~/anaconda3/envs/nis2pyr/lib/python3.8/site-packages/ome_types/model/init.py:1
----> 1 from .affine_transform import AffineTransform
2 from .annotation import Annotation
3 from .annotation_ref import AnnotationRef

File ~/anaconda3/envs/nis2pyr/lib/python3.8/site-packages/ome_types/model/affine_transform.py:1
----> 1 from ome_types._base_type import OMEType
4 class AffineTransform(OMEType):
5 """A matrix used to transform the shape.
6
7 ⎡ A00, A01, A02 ⎤ ⎢ A10, A11, A12 ⎥ ⎣ 0, 0, 1 ⎦
(...)
16 a12 : float
17 """

File ~/anaconda3/envs/nis2pyr/lib/python3.8/site-packages/ome_types/_base_type.py:13
1 from typing import (
2 TYPE_CHECKING,
3 Any,
(...)
9 no_type_check,
10 )
12 from pydantic import BaseModel, validator
---> 13 from pydantic.main import ModelMetaclass
15 if TYPE_CHECKING:
16 import pint

ImportError: cannot import name 'ModelMetaclass' from 'pydantic.main' (/home/kuanwei/anaconda3/envs/nis2pyr/lib/python3.8/site-packages/pydantic/main.py)