メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.5125000 42.5125000, 142.5187500 42.5125000, 142.5187500 42.5166667, 142.5125000 42.5166667, 142.5125000 42.5125000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral