メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8062500 42.8500000, 141.8125000 42.8500000, 141.8125000 42.8541667, 141.8062500 42.8541667, 141.8062500 42.8500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral