メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.4812500 33.2916667, 131.4875000 33.2916667, 131.4875000 33.2958334, 131.4812500 33.2958334, 131.4812500 33.2916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral