import gzip
import shutil


def _gunzip(gz_file: str, gunzipped_file: str) -> bool:
    """
    unzips `gz_file` and saves the contents as `gunzipped_file`
    """
    # see 'https://stackoverflow.com/questions/48466421/python-how-to-'
    #     'decompress-a-gzip-file-to-an-uncompressed-file-on-disk'
    with gzip.open(gz_file, 'r') as f_in, \
            open(gunzipped_file, 'wb') as f_out:
        shutil.copyfileobj(f_in, f_out)

    return True