メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((140.9812500 43.1916667, 140.9875000 43.1916667, 140.9875000 43.1958334, 140.9812500 43.1958334, 140.9812500 43.1916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral