メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4625000 43.5791667, 142.4687500 43.5791667, 142.4687500 43.5833333, 142.4625000 43.5833333, 142.4625000 43.5791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral