メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.1875000 43.5208334, 142.1937500 43.5208334, 142.1937500 43.5250000, 142.1875000 43.5250000, 142.1875000 43.5208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral