メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.4187500 31.9666667, 131.4250000 31.9666667, 131.4250000 31.9708334, 131.4187500 31.9708334, 131.4187500 31.9666667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral