メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((140.3625000 42.4916667, 140.3687500 42.4916667, 140.3687500 42.4958334, 140.3625000 42.4958334, 140.3625000 42.4916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral