メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.2187500 43.4833333, 142.2250000 43.4833333, 142.2250000 43.4875000, 142.2187500 43.4875000, 142.2187500 43.4833333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral