メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.1750000 44.6916667, 142.1812500 44.6916667, 142.1812500 44.6958334, 142.1750000 44.6958334, 142.1750000 44.6916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral