メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.9937500 38.9958334, 140.0000000 38.9958334, 140.0000000 39.0000000, 139.9937500 39.0000000, 139.9937500 38.9958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral