メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.2687500 36.7458334, 138.2750000 36.7458334, 138.2750000 36.7500000, 138.2687500 36.7500000, 138.2687500 36.7458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral