メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.7875000 44.4666667, 141.7937500 44.4666667, 141.7937500 44.4708334, 141.7875000 44.4708334, 141.7875000 44.4666667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral