メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.2687500 31.9958334, 131.2750000 31.9958334, 131.2750000 32.0000000, 131.2687500 32.0000000, 131.2687500 31.9958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral