メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.8375000 36.9333333, 138.8437500 36.9333333, 138.8437500 36.9375000, 138.8375000 36.9375000, 138.8375000 36.9333333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral