メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.4312500 31.9916667, 131.4375000 31.9916667, 131.4375000 31.9958334, 131.4312500 31.9958334, 131.4312500 31.9916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral