メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.3000000 42.1875000, 143.3062500 42.1875000, 143.3062500 42.1916667, 143.3000000 42.1916667, 143.3000000 42.1875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral