メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.3750000 36.9166667, 138.3812500 36.9166667, 138.3812500 36.9208334, 138.3750000 36.9208334, 138.3750000 36.9166667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral