メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.9000000 37.6750000, 138.9062500 37.6750000, 138.9062500 37.6791667, 138.9000000 37.6791667, 138.9000000 37.6750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral