メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.7875000 44.6708334, 142.7937500 44.6708334, 142.7937500 44.6750000, 142.7875000 44.6750000, 142.7875000 44.6708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral