メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.2937500 34.8458334, 138.3000000 34.8458334, 138.3000000 34.8500000, 138.2937500 34.8500000, 138.2937500 34.8458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral