メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.5187500 38.5333333, 141.5250000 38.5333333, 141.5250000 38.5375000, 141.5187500 38.5375000, 141.5187500 38.5333333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral