メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.5187500 43.8333333, 142.5250000 43.8333333, 142.5250000 43.8375000, 142.5187500 43.8375000, 142.5187500 43.8333333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral