メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.2312500 43.1500000, 141.2375000 43.1500000, 141.2375000 43.1541667, 141.2312500 43.1541667, 141.2312500 43.1500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral