メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8375000 43.2875000, 141.8437500 43.2875000, 141.8437500 43.2916667, 141.8375000 43.2916667, 141.8375000 43.2875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral