メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.6812500 37.2750000, 138.6875000 37.2750000, 138.6875000 37.2791667, 138.6812500 37.2791667, 138.6812500 37.2750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral