メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.6875000 36.0541667, 138.6937500 36.0541667, 138.6937500 36.0583333, 138.6875000 36.0583333, 138.6875000 36.0541667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral