メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8625000 42.6375000, 141.8687500 42.6375000, 141.8687500 42.6416667, 141.8625000 42.6416667, 141.8625000 42.6375000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral