メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.1625000 42.4750000, 141.1687500 42.4750000, 141.1687500 42.4791667, 141.1625000 42.4791667, 141.1625000 42.4750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral