メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.348882270696 43.7752448568526, 142.349114211394 43.7756602320437, 142.347722665893 43.7760669832113, 142.347477873376 43.7756692662831, 142.347250594032 43.7752542872174, 142.348659560074 43.7748261334216, 142.348882270696 43.7752448568526)) ^^http://www.opengis.net/ont/geosparql#wktLiteral