メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.8750000 37.6875000, 138.8812500 37.6875000, 138.8812500 37.6916667, 138.8750000 37.6916667, 138.8750000 37.6875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral