メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.0375000 31.7625000, 131.0437500 31.7625000, 131.0437500 31.7666667, 131.0375000 31.7666667, 131.0375000 31.7625000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral