メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4750000 44.3750000, 142.4812500 44.3750000, 142.4812500 44.3791667, 142.4750000 44.3791667, 142.4750000 44.3750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral