メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4437500 43.8291667, 142.4500000 43.8291667, 142.4500000 43.8333333, 142.4437500 43.8333333, 142.4437500 43.8291667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral