メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4312500 44.3458334, 142.4375000 44.3458334, 142.4375000 44.3500000, 142.4312500 44.3500000, 142.4312500 44.3458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral