メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.2500000 31.4708334, 131.2562500 31.4708334, 131.2562500 31.4750000, 131.2500000 31.4750000, 131.2500000 31.4708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral