メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((140.8000000 43.1833333, 140.8062500 43.1833333, 140.8062500 43.1875000, 140.8000000 43.1875000, 140.8000000 43.1833333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral