メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.8937500 43.0208334, 142.9000000 43.0208334, 142.9000000 43.0250000, 142.8937500 43.0250000, 142.8937500 43.0208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral