メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.4750000 38.7666667, 141.4812500 38.7666667, 141.4812500 38.7708334, 141.4750000 38.7708334, 141.4750000 38.7666667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral