メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.8312500 43.0833333, 142.8375000 43.0833333, 142.8375000 43.0875000, 142.8312500 43.0875000, 142.8312500 43.0833333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral