メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8937500 43.4541667, 141.9000000 43.4541667, 141.9000000 43.4583333, 141.8937500 43.4583333, 141.8937500 43.4541667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral