メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3812500 36.3916667, 138.3875000 36.3916667, 138.3875000 36.3958334, 138.3812500 36.3958334, 138.3812500 36.3916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral