メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.1062500 36.0416667, 138.1125000 36.0416667, 138.1125000 36.0458334, 138.1062500 36.0458334, 138.1062500 36.0416667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral