メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.5750000 42.8833333, 143.5812500 42.8833333, 143.5812500 42.8875000, 143.5750000 42.8875000, 143.5750000 42.8833333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral