メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4312500 43.4458334, 142.4375000 43.4458334, 142.4375000 43.4500000, 142.4312500 43.4500000, 142.4312500 43.4458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral