メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.0187500 36.3166667, 138.0250000 36.3166667, 138.0250000 36.3208334, 138.0187500 36.3208334, 138.0187500 36.3166667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral