メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.9375000 42.6750000, 141.9437500 42.6750000, 141.9437500 42.6791667, 141.9375000 42.6791667, 141.9375000 42.6750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral