メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.1437500 44.1333333, 142.1500000 44.1333333, 142.1500000 44.1375000, 142.1437500 44.1375000, 142.1437500 44.1333333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral