メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.9437500 37.6708334, 138.9500000 37.6708334, 138.9500000 37.6750000, 138.9437500 37.6750000, 138.9437500 37.6708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral