メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.0000000 31.3750000, 131.0062500 31.3750000, 131.0062500 31.3791667, 131.0000000 31.3791667, 131.0000000 31.3750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral