メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3687500 38.0458334, 138.3750000 38.0458334, 138.3750000 38.0500000, 138.3687500 38.0500000, 138.3687500 38.0458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral