メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.1750000 31.9000000, 131.1812500 31.9000000, 131.1812500 31.9041667, 131.1750000 31.9041667, 131.1750000 31.9000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral