メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((140.6875000 42.6125000, 140.6937500 42.6125000, 140.6937500 42.6166667, 140.6875000 42.6166667, 140.6875000 42.6125000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral