def get_lazo_sketches(data_profile, filter_=None):
    """
    Get Lazo sketches of the input dataset, if available.

    :param data_profile: Profiled input dataset.
    :param filter_: list of column indices to return.
       If an empty list, return all the columns.
    :return: dict, where key is the column index, and value is a tuple
        (n_permutations, hash_values, cardinality)
    """

    lazo_sketches = dict()

    for column_index, column in enumerate(data_profile['columns']):
        if 'lazo' in column:
            if not filter_ or column_index in filter_:
                lazo_sketches[(column_index,)] = (
                    column['lazo']['n_permutations'],
                    column['lazo']['hash_values'],
                    column['lazo']['cardinality'],
                )

    return lazo_sketches