メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.0375000 45.4041667, 141.0437500 45.4041667, 141.0437500 45.4083333, 141.0375000 45.4083333, 141.0375000 45.4041667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral