メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.0875000 42.4083333, 141.0937500 42.4083333, 141.0937500 42.4125000, 141.0875000 42.4125000, 141.0875000 42.4083333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral