メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.0125000 31.4083333, 131.0187500 31.4083333, 131.0187500 31.4125000, 131.0125000 31.4125000, 131.0125000 31.4083333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral