メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.5187500 43.1166667, 141.5250000 43.1166667, 141.5250000 43.1208334, 141.5187500 43.1208334, 141.5187500 43.1166667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral