メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((140.4937500 40.2458334, 140.5000000 40.2458334, 140.5000000 40.2500000, 140.4937500 40.2500000, 140.4937500 40.2458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral