メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.8437500 37.1458334, 138.8500000 37.1458334, 138.8500000 37.1500000, 138.8437500 37.1500000, 138.8437500 37.1458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral