メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.4687500 31.9458334, 131.4750000 31.9458334, 131.4750000 31.9500000, 131.4687500 31.9500000, 131.4687500 31.9458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral