メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.0812500 38.9958334, 141.0875000 38.9958334, 141.0875000 39.0000000, 141.0812500 39.0000000, 141.0812500 38.9958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral