メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.7812500 44.7333333, 141.7875000 44.7333333, 141.7875000 44.7375000, 141.7812500 44.7375000, 141.7812500 44.7333333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral