メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.9437500 42.5958334, 141.9500000 42.5958334, 141.9500000 42.6000000, 141.9437500 42.6000000, 141.9437500 42.5958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral