modeling_test.py

from transformers import PreTrainedModel
from .configuration_test import TestConfig
import torch.nn as nn
from transformers import AutoModelForMaskedLM, AutoConfig
from transformers import AutoModelForSequenceClassification


class TestModel(PreTrainedModel):
    config_class = TestConfig

    def __init__(self, config: TestConfig):
        super().__init__(config)
        self.input_dim = config.input_dim
        self.model1 = nn.Linear(config.input_dim, config.output_dim)
        self.model2 = AutoModelForMaskedLM.from_config(
            AutoConfig.from_pretrained("albert/albert-base-v2")
        )

    def forward(self, tensor):
        return self.model1(tensor)