from typing import Dict
import aiohttp


async def head(url: str) -> Dict:
    """Fetch headers returned http GET request.

    :param str url:
        The URL to perform the GET request for.
    :rtype: dict
    :returns:
        dictionary of lowercase headers
    """
    async with aiohttp.request("HEAD", url) as res:
        response_headers = res.headers
        return {k.lower(): v for k, v in response_headers.items()}