メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8250000 43.2750000, 141.8312500 43.2750000, 141.8312500 43.2791667, 141.8250000 43.2791667, 141.8250000 43.2750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral