メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.7687500 37.1958334, 138.7750000 37.1958334, 138.7750000 37.2000000, 138.7687500 37.2000000, 138.7687500 37.1958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral