メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.7625000 42.1791667, 142.7687500 42.1791667, 142.7687500 42.1833333, 142.7625000 42.1833333, 142.7625000 42.1791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral