メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.9437500 42.8958334, 143.9500000 42.8958334, 143.9500000 42.9000000, 143.9437500 42.9000000, 143.9437500 42.8958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral