メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8812500 42.5833333, 141.8875000 42.5833333, 141.8875000 42.5875000, 141.8812500 42.5875000, 141.8812500 42.5833333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral