メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.8437500 35.0958334, 138.8500000 35.0958334, 138.8500000 35.1000000, 138.8437500 35.1000000, 138.8437500 35.0958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral