def download_har_dataset():
    """
    Download human activity recognition dataset from UCI ML Repository and store it at /tsfresh/notebooks/data.
    
    Examples
    ========

    >>> from tsfresh.examples import har_dataset
    >>> har_dataset.download_har_dataset()
    """

    zipurl = 'https://github.com/MaxBenChrist/human-activity-dataset/blob/master/UCI%20HAR%20Dataset.zip?raw=true'

    if os.path.exists(data_file_name_dataset) and os.path.exists(data_file_name_classes):
        _logger.warning("You have already downloaded the Human Activity Data Set.")
        return

    with urlopen(zipurl) as zipresp:
        with ZipFile(BytesIO(zipresp.read())) as zfile:
            zfile.extractall(path=data_file_name)
        zfile.close()