メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.446815228039 43.7736768015903, 142.445152369894 43.7737766512869, 142.445094891493 43.7732994054084, 142.446354774747 43.7732476589697, 142.446762476366 43.7732165850085, 142.448554209616 43.7731291805699, 142.448611164072 43.7735689593466, 142.446815228039 43.7736768015903)) ^^http://www.opengis.net/ont/geosparql#wktLiteral