メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.6375000 37.6916667, 139.6437500 37.6916667, 139.6437500 37.6958334, 139.6375000 37.6958334, 139.6375000 37.6916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral