メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((145.3125000 44.1833333, 145.3187500 44.1833333, 145.3187500 44.1875000, 145.3125000 44.1875000, 145.3125000 44.1833333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral