メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3625000 34.9375000, 138.3687500 34.9375000, 138.3687500 34.9416667, 138.3625000 34.9416667, 138.3625000 34.9375000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral