メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4375000 42.4416667, 142.4437500 42.4416667, 142.4437500 42.4458334, 142.4375000 42.4458334, 142.4375000 42.4416667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral