メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.2437500 36.8958334, 138.2500000 36.8958334, 138.2500000 36.9000000, 138.2437500 36.9000000, 138.2437500 36.8958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral