メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.1625000 36.8583333, 138.1687500 36.8583333, 138.1687500 36.8625000, 138.1625000 36.8625000, 138.1625000 36.8583333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral