メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.5312500 43.8208334, 142.5375000 43.8208334, 142.5375000 43.8250000, 142.5312500 43.8250000, 142.5312500 43.8208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral