メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.2500000 43.1416667, 141.2562500 43.1416667, 141.2562500 43.1458334, 141.2500000 43.1458334, 141.2500000 43.1416667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral