メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.4187500 43.0916667, 141.4250000 43.0916667, 141.4250000 43.0958334, 141.4187500 43.0958334, 141.4187500 43.0916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral