メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.8375000 37.4375000, 138.8437500 37.4375000, 138.8437500 37.4416667, 138.8375000 37.4416667, 138.8375000 37.4375000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral