メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.5625000 36.5125000, 138.5687500 36.5125000, 138.5687500 36.5166667, 138.5625000 36.5166667, 138.5625000 36.5125000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral