メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3125000 36.6333333, 138.3187500 36.6333333, 138.3187500 36.6375000, 138.3125000 36.6375000, 138.3125000 36.6333333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral