メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.5687500 44.5416667, 142.5750000 44.5416667, 142.5750000 44.5458334, 142.5687500 44.5458334, 142.5687500 44.5416667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral