def split_data_interp(data_dict):
    """
    Split data into observed and to predict for interpolation task.
    """
    data_ = data_dict["data"]
    time_ = data_dict["time_steps"]
    split_dict = {"observed_data": data_,
                  "observed_tp": time_,
                  "data_to_predict": data_,
                  "tp_to_predict": time_,
                  "observed_mask": None,
                  "mask_predicted_data": None
                  }

    if "mask" in data_dict and data_dict["mask"] is not None:
        mask_ = data_dict["mask"]
        split_dict["observed_mask"] = mask_
        split_dict["mask_predicted_data"] = mask_

    return split_dict