メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.6375000 45.3958334, 141.6437500 45.3958334, 141.6437500 45.4000000, 141.6375000 45.4000000, 141.6375000 45.3958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral