メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3125000 38.0333333, 138.3187500 38.0333333, 138.3187500 38.0375000, 138.3125000 38.0375000, 138.3125000 38.0333333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral