メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.3375000 43.8083333, 142.3437500 43.8083333, 142.3437500 43.8125000, 142.3375000 43.8125000, 142.3375000 43.8083333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral