メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.0937500 31.4958334, 131.1000000 31.4958334, 131.1000000 31.5000000, 131.0937500 31.5000000, 131.0937500 31.4958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral