メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.5375000 42.8125000, 143.5437500 42.8125000, 143.5437500 42.8166667, 143.5375000 42.8166667, 143.5375000 42.8125000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral