メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.9312500 42.6583333, 141.9375000 42.6583333, 141.9375000 42.6625000, 141.9312500 42.6625000, 141.9312500 42.6583333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral