メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.7812500 43.1916667, 141.7875000 43.1916667, 141.7875000 43.1958334, 141.7812500 43.1958334, 141.7812500 43.1916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral