メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.9937500 37.9000000, 139.0000000 37.9000000, 139.0000000 37.9041667, 138.9937500 37.9041667, 138.9937500 37.9000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral