メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.0062500 42.9666667, 142.0125000 42.9666667, 142.0125000 42.9708334, 142.0062500 42.9708334, 142.0062500 42.9666667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral