''

def __init__(self, layer, tileset):

    sethref = urljoin(layer.config.dirpath, tileset)
    (scheme, h, path, q, p, f) = urlparse(sethref)
    if (scheme not in ('file', '')):
        raise Exception(('Bad    scheme    in    MBTiles    provider,    must    be    local    file:    "%s"' % scheme))
    self.tileset = path
    self.layer = layer
