def get(self, *args, **kwargs):
        '''Service a GET request to the '/map' URI.

        The 'bbox' parameter contains 4 coordinates "l" (w), "b" (s),
        "r" (e) and "t" (n).'''
        
        # Sanity check the input.
        bbox_arg = self.get_argument('bbox', None)
        if not bbox_arg:
            raise tornado.web.HTTPError(400)  # Bad Syntax
        bbox = bbox_arg.split(',')
        if len(bbox) != 4:
            raise tornado.web.HTTPError(400)
        try:
            w,s,e,n = map(float, bbox)
        except __HOLE__:
            raise tornado.web.HTTPError(400)

        # Check the "l,b,r,t" coordinates passed in for sanity.
        if w < C.LON_MIN or w > C.LON_MAX or \
           e < C.LON_MIN or e > C.LON_MAX or \
           s < C.LAT_MIN or s > C.LAT_MAX or \
           n < C.LAT_MIN or n > C.LAT_MAX or \
           n < s or e < w:
            raise tornado.web.HTTPError(400)

        nodelist, ways, relations = self.handle_map(bbox)
        response = self.build_bbox_response(nodelist, ways, relations, bbox)

        self.set_header(C.CONTENT_TYPE, C.TEXT_XML)
        self.write(response_to_xml(response))
dataset/ETHPy150Open MapQuest/mapquest-osm-server/src/python/frontend/maphandler.py/MapHandler.get