メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.1437500 36.5750000, 138.1500000 36.5750000, 138.1500000 36.5791667, 138.1437500 36.5791667, 138.1437500 36.5750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral