メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.4812500 35.7083333, 138.4875000 35.7083333, 138.4875000 35.7125000, 138.4812500 35.7125000, 138.4812500 35.7083333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral