Base64 encode using URL-safe encoding with padding removed.

    @param b bytes to decode
    @return bytes decoded

def raw_urlsafe_b64encode(b):
    '''Base64 encode using URL-safe encoding with padding removed.

    @param b bytes to decode
    @return bytes decoded
    '''
    b = to_bytes(b)
    b = base64.urlsafe_b64encode(b)
    b = b.rstrip(b'=')  # strip padding
    return b