class_docstr: A Masked Language Model for Finetune
  
  :param config: A :py:class:`finetune.config.Settings` object or None (for default config).
  :param \**kwargs: key-value pairs of config items to override.
code: def __init__(self, *args, **kwargs):
      super().__init__(*args, **kwargs)
      if not issubclass(self.config.base_model, (BERT, RoBERTa)):
          raise FinetuneError(
              "MLM training is currently only supported for BERT and RoBERTa base models."
          )
  
imports: import tensorflow
  from tensorflow import TensorShape
  import numpy
  from finetune.errors import FinetuneError
  from finetune.base import PredictMode, BaseModel
  from finetune.base_models import RoBERTa, BERT
  from finetune.input_pipeline import BasePipeline
  from finetune.nn.target_blocks import masked_language_model
label_desc: Use image node_id 1 to create a new MaskedLanguageModel object from inherited base classes: BaseModel with example: obj = MaskedLanguageModel()