メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.2687500 34.7916667, 138.2750000 34.7916667, 138.2750000 34.7958334, 138.2687500 34.7958334, 138.2687500 34.7916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral