メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.2187500 45.0416667, 142.2250000 45.0416667, 142.2250000 45.0458334, 142.2187500 45.0458334, 142.2187500 45.0416667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral