メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8562500 43.3791667, 141.8625000 43.3791667, 141.8625000 43.3833333, 141.8562500 43.3833333, 141.8562500 43.3791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral