メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.9000000 37.5750000, 138.9062500 37.5750000, 138.9062500 37.5791667, 138.9000000 37.5791667, 138.9000000 37.5750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral