メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.3812500 31.5416667, 131.3875000 31.5416667, 131.3875000 31.5458334, 131.3812500 31.5458334, 131.3812500 31.5416667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral