メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.7375000 37.5791667, 138.7437500 37.5791667, 138.7437500 37.5833333, 138.7375000 37.5833333, 138.7375000 37.5791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral