メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8625000 42.7333333, 141.8687500 42.7333333, 141.8687500 42.7375000, 141.8625000 42.7375000, 141.8625000 42.7333333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral