メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8375000 45.0750000, 141.8437500 45.0750000, 141.8437500 45.0791667, 141.8375000 45.0791667, 141.8375000 45.0750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral