メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.1625000 36.6291667, 138.1687500 36.6291667, 138.1687500 36.6333333, 138.1625000 36.6333333, 138.1625000 36.6291667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral