メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.6937500 45.1875000, 141.7000000 45.1875000, 141.7000000 45.1916667, 141.6937500 45.1916667, 141.6937500 45.1875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral