メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3937500 36.2416667, 138.4000000 36.2416667, 138.4000000 36.2458334, 138.3937500 36.2458334, 138.3937500 36.2416667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral