メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.0187500 31.7208334, 131.0250000 31.7208334, 131.0250000 31.7250000, 131.0187500 31.7250000, 131.0187500 31.7208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral