メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3375000 36.7416667, 138.3437500 36.7416667, 138.3437500 36.7458334, 138.3375000 36.7458334, 138.3375000 36.7416667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral