メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.5812500 35.5041667, 138.5875000 35.5041667, 138.5875000 35.5083333, 138.5812500 35.5083333, 138.5812500 35.5041667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral