メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.2125000 43.4958334, 142.2187500 43.4958334, 142.2187500 43.5000000, 142.2125000 43.5000000, 142.2125000 43.4958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral