メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.2500000 44.5375000, 142.2562500 44.5375000, 142.2562500 44.5416667, 142.2500000 44.5416667, 142.2500000 44.5375000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral