メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.9000000 43.3500000, 141.9062500 43.3500000, 141.9062500 43.3541667, 141.9000000 43.3541667, 141.9000000 43.3500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral