メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.0250000 43.1625000, 141.0312500 43.1625000, 141.0312500 43.1666667, 141.0250000 43.1666667, 141.0250000 43.1625000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral