メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3687500 37.9666667, 138.3750000 37.9666667, 138.3750000 37.9708334, 138.3687500 37.9708334, 138.3687500 37.9666667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral