メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.0875000 36.3875000, 138.0937500 36.3875000, 138.0937500 36.3916667, 138.0875000 36.3916667, 138.0875000 36.3875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral