メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.2875000 35.9833333, 138.2937500 35.9833333, 138.2937500 35.9875000, 138.2875000 35.9875000, 138.2875000 35.9833333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral