メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.5750000 38.5208334, 139.5812500 38.5208334, 139.5812500 38.5250000, 139.5750000 38.5250000, 139.5750000 38.5208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral