def save_submissions(problem, y_pred, data_path='.', output_path='.',
    suffix='test'):
    """Custom save a prediction vector in file to, e.g., submit to Kaggle.

    If problem.save_submission is implemented, y_pred is passed to it.
    Otherwise nothing happens (the exception is caught silently).

    Parameters
    ----------
    problem : a problem object
        loaded from problem.py, may implement save_y_pred
    y_pred : a prediction vector
        a vector of predictions to be saved
    data_path : str, (default='.')
        the directory of the ramp-kit to be tested for submission, maybe
        needed by problem.save_y_pred for, e.g., merging with an index vector
    output_path : str, (default='.')
        the directory where (typically) y_pred_<suffix>.csv will be saved
    suffix : str, (default='test')
        suffix in (typically) y_pred_<suffix>.csv, can be used in
        problem.save_y_pred to, e.g., save only test predictions
    """
    try:
        problem.save_submission(y_pred, data_path, output_path, suffix)
    except AttributeError:
        pass
