メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.6875000 37.4666667, 138.6937500 37.4666667, 138.6937500 37.4708334, 138.6875000 37.4708334, 138.6875000 37.4666667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral