メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.1812500 43.4916667, 142.1875000 43.4916667, 142.1875000 43.4958334, 142.1812500 43.4958334, 142.1812500 43.4916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral