from tensorflow.contrib import layers

        bias variable for each class. Rest of the model structure learns the
        residual after centered bias.
      target_dimension: TODO(zakaria): dimension of the target for multilabels.
      config: RunConfig object to configure the runtime settings.

    Raises:
      ValueError: If both linear_feature_columns and dnn_features_columns are
        empty at the same time.
    """
    target_column = layers.regression_target(
        weight_column_name=weight_column_name,
        target_dimension=target_dimension)
    super(DNNLinearCombinedRegressor, self).__init__(
        model_dir=model_dir,
        linear_feature_columns=linear_feature_columns,
        linear_optimizer=linear_optimizer,
        dnn_feature_columns=dnn_feature_columns,
        dnn_optimizer=dnn_optimizer,
