メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.1937500 36.0208334, 138.2000000 36.0208334, 138.2000000 36.0250000, 138.1937500 36.0250000, 138.1937500 36.0208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral