メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.3812500 43.3458334, 142.3875000 43.3458334, 142.3875000 43.3500000, 142.3812500 43.3500000, 142.3812500 43.3458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral