メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.6937500 36.9083333, 138.7000000 36.9083333, 138.7000000 36.9125000, 138.6937500 36.9125000, 138.6937500 36.9083333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral