メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.3750000 31.5125000, 131.3812500 31.5125000, 131.3812500 31.5166667, 131.3750000 31.5166667, 131.3750000 31.5125000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral