メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.2875000 36.5833333, 138.2937500 36.5833333, 138.2937500 36.5875000, 138.2875000 36.5875000, 138.2875000 36.5833333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral