メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.5750000 37.4041667, 138.5812500 37.4041667, 138.5812500 37.4083333, 138.5750000 37.4083333, 138.5750000 37.4041667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral