メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.7750000 42.1916667, 142.7812500 42.1916667, 142.7812500 42.1958334, 142.7750000 42.1958334, 142.7750000 42.1916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral