メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.0312500 42.9458334, 142.0375000 42.9458334, 142.0375000 42.9500000, 142.0312500 42.9500000, 142.0312500 42.9458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral