メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.2562500 38.0833333, 138.2625000 38.0833333, 138.2625000 38.0875000, 138.2562500 38.0875000, 138.2562500 38.0833333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral