メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.9000000 43.4708334, 141.9062500 43.4708334, 141.9062500 43.4750000, 141.9000000 43.4750000, 141.9000000 43.4708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral