メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.5687500 43.2458334, 141.5750000 43.2458334, 141.5750000 43.2500000, 141.5687500 43.2500000, 141.5687500 43.2458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral