メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.7937500 43.3541667, 141.8000000 43.3541667, 141.8000000 43.3583333, 141.7937500 43.3583333, 141.7937500 43.3541667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral