メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.5750000 43.8875000, 142.5812500 43.8875000, 142.5812500 43.8916667, 142.5750000 43.8916667, 142.5750000 43.8875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral