メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.2625000 44.8250000, 142.2687500 44.8250000, 142.2687500 44.8291667, 142.2625000 44.8291667, 142.2625000 44.8250000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral