メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.0750000 35.8500000, 138.0812500 35.8500000, 138.0812500 35.8541667, 138.0750000 35.8541667, 138.0750000 35.8500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral