メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3125000 36.8000000, 138.3187500 36.8000000, 138.3187500 36.8041667, 138.3125000 36.8041667, 138.3125000 36.8000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral