メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.5937500 37.4166667, 138.6000000 37.4166667, 138.6000000 37.4208334, 138.5937500 37.4208334, 138.5937500 37.4166667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral