メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8187500 43.3000000, 141.8250000 43.3000000, 141.8250000 43.3041667, 141.8187500 43.3041667, 141.8187500 43.3000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral