メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8625000 43.2916667, 141.8687500 43.2916667, 141.8687500 43.2958334, 141.8625000 43.2958334, 141.8625000 43.2916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral