メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.5375000 37.1750000, 138.5437500 37.1750000, 138.5437500 37.1791667, 138.5375000 37.1791667, 138.5375000 37.1750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral