メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.5687500 37.3750000, 138.5750000 37.3750000, 138.5750000 37.3791667, 138.5687500 37.3791667, 138.5687500 37.3750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral