メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.5375000 38.0041667, 138.5437500 38.0041667, 138.5437500 38.0083333, 138.5375000 38.0083333, 138.5375000 38.0041667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral