メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.8750000 42.9916667, 142.8812500 42.9916667, 142.8812500 42.9958334, 142.8750000 42.9958334, 142.8750000 42.9916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral