メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.0750000 37.4916667, 139.0812500 37.4916667, 139.0812500 37.4958334, 139.0750000 37.4958334, 139.0750000 37.4916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral