メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.2187500 34.7833333, 138.2250000 34.7833333, 138.2250000 34.7875000, 138.2187500 34.7875000, 138.2187500 34.7833333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral