メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.1812500 36.8708334, 138.1875000 36.8708334, 138.1875000 36.8750000, 138.1812500 36.8750000, 138.1812500 36.8708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral