メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.1500000 36.8916667, 138.1562500 36.8916667, 138.1562500 36.8958334, 138.1500000 36.8958334, 138.1500000 36.8916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral