メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.5375000 43.2916667, 142.5437500 43.2916667, 142.5437500 43.2958334, 142.5375000 43.2958334, 142.5375000 43.2916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral