メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8250000 43.2958334, 141.8312500 43.2958334, 141.8312500 43.3000000, 141.8250000 43.3000000, 141.8250000 43.2958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral