メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3437500 36.8791667, 138.3500000 36.8791667, 138.3500000 36.8833333, 138.3437500 36.8833333, 138.3437500 36.8791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral