メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4375000 43.6708334, 142.4437500 43.6708334, 142.4437500 43.6750000, 142.4375000 43.6750000, 142.4375000 43.6708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral