メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.7937500 42.1666667, 142.8000000 42.1666667, 142.8000000 42.1708334, 142.7937500 42.1708334, 142.7937500 42.1666667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral