メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.3187500 40.6708334, 141.3250000 40.6708334, 141.3250000 40.6750000, 141.3187500 40.6750000, 141.3187500 40.6708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral