メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.1875000 36.9875000, 138.1937500 36.9875000, 138.1937500 36.9916667, 138.1875000 36.9916667, 138.1875000 36.9875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral