def __validate_scikit_params(parameters):
    """validate scikit-learn DBSCAN parameters

    Args:
        parameters: (dict)
    Returns:
        eps, min_samples, metric, n_jobs
    """
    eps, min_samples, metric, n_jobs = None, None, None, None

    if parameters is not None:
        eps = parameters.get('eps')
        min_samples = parameters.get('min_samples')
        metric = parameters.get('metric')
        n_jobs = parameters.get('n_jobs')
    else:
        pass

    # set default values if the dictionary didn't contain correct keys
    eps = 0.005 if eps is None else eps
    min_samples = 100 if min_samples is None else min_samples
    metric = 'euclidean' if metric is None else metric
    n_jobs = -1 if n_jobs is None else n_jobs

    return eps, min_samples, metric, n_jobs