code: def feed_shape_type_def(self):
      return (
          (
              {
                  "tokens": tf.int32,
                  "mlm_weights": tf.float32,
                  "mlm_ids": tf.int32,
                  "mlm_positions": tf.int32,
              },
          ),
          (
              {
                  "tokens": TS([None]),
                  "mlm_weights": TS([None]),
                  "mlm_ids": TS([None]),
                  "mlm_positions": TS([None]),
              },
          ),
      )
  
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 2 for calling the MaskedLanguageModelPipeline obj's underlying member method code with example usage: obj.feed_shape_type_def() and returns: dict,  dict