メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8000000 43.1541667, 141.8062500 43.1541667, 141.8062500 43.1583333, 141.8000000 43.1583333, 141.8000000 43.1541667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral