src/transformers/models/convbert/modeling_tf_convbert.py/TFConvBertMaskedLMHead/build
class TFConvBertMaskedLMHead:    def build(self, input_shape):
        self.bias = self.add_weight(shape=(self.vocab_size,), initializer="zeros", trainable=True, name="bias")

        super().build(input_shape)