メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4125000 43.7833333, 142.4187500 43.7833333, 142.4187500 43.7875000, 142.4125000 43.7875000, 142.4125000 43.7833333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral