メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.0375000 43.6958334, 142.0437500 43.6958334, 142.0437500 43.7000000, 142.0375000 43.7000000, 142.0375000 43.6958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral