メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.4937500 36.3458334, 138.5000000 36.3458334, 138.5000000 36.3500000, 138.4937500 36.3500000, 138.4937500 36.3458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral