メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.9437500 36.5500000, 138.9500000 36.5500000, 138.9500000 36.5541667, 138.9437500 36.5541667, 138.9437500 36.5500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral