メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.8250000 37.5916667, 138.8312500 37.5916667, 138.8312500 37.5958334, 138.8250000 37.5958334, 138.8250000 37.5916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral