メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.3750000 44.1791667, 142.3812500 44.1791667, 142.3812500 44.1833333, 142.3750000 44.1833333, 142.3750000 44.1791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral