メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.5000000 42.8458334, 141.5062500 42.8458334, 141.5062500 42.8500000, 141.5000000 42.8500000, 141.5000000 42.8458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral