メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.1625000 42.9916667, 143.1687500 42.9916667, 143.1687500 42.9958334, 143.1625000 42.9958334, 143.1625000 42.9916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral