メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.3375000 44.4750000, 142.3437500 44.4750000, 142.3437500 44.4791667, 142.3375000 44.4791667, 142.3375000 44.4750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral