メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.9250000 38.9666667, 139.9312500 38.9666667, 139.9312500 38.9708334, 139.9250000 38.9708334, 139.9250000 38.9666667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral