メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.2250000 42.8083333, 142.2312500 42.8083333, 142.2312500 42.8125000, 142.2250000 42.8125000, 142.2250000 42.8083333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral