メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3312500 38.1916667, 138.3375000 38.1916667, 138.3375000 38.1958334, 138.3312500 38.1958334, 138.3312500 38.1916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral