メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.6250000 36.4625000, 138.6312500 36.4625000, 138.6312500 36.4666667, 138.6250000 36.4666667, 138.6250000 36.4625000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral