メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.5250000 43.2250000, 142.5312500 43.2250000, 142.5312500 43.2291667, 142.5250000 43.2291667, 142.5250000 43.2250000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral