メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.6750000 43.9041667, 141.6812500 43.9041667, 141.6812500 43.9083333, 141.6750000 43.9083333, 141.6750000 43.9041667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral