メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.1375000 36.5208334, 138.1437500 36.5208334, 138.1437500 36.5250000, 138.1375000 36.5250000, 138.1375000 36.5208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral