:param fileobj: a file object
    :return: a hash of the file content

def hash_file(fileobj):
    """
    :param fileobj: a file object
    :return: a hash of the file content
    """
    hasher = hashlib.md5()
    buf = fileobj.read(65536)
    while len(buf) > 0:
        hasher.update(buf)
        buf = fileobj.read(65536)
    return hasher.hexdigest()