メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3187500 36.3791667, 138.3250000 36.3791667, 138.3250000 36.3833333, 138.3187500 36.3833333, 138.3187500 36.3791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral