メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.0062500 30.5500000, 131.0125000 30.5500000, 131.0125000 30.5541667, 131.0062500 30.5541667, 131.0062500 30.5500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral