メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.7937500 34.6583333, 138.8000000 34.6583333, 138.8000000 34.6625000, 138.7937500 34.6625000, 138.7937500 34.6583333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral