メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8437500 45.0166667, 141.8500000 45.0166667, 141.8500000 45.0208334, 141.8437500 45.0208334, 141.8437500 45.0166667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral