メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.2812500 38.1083333, 138.2875000 38.1083333, 138.2875000 38.1125000, 138.2812500 38.1125000, 138.2812500 38.1083333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral