メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.8125000 35.4750000, 138.8187500 35.4750000, 138.8187500 35.4791667, 138.8125000 35.4791667, 138.8125000 35.4750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral