メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.4625000 42.9916667, 141.4687500 42.9916667, 141.4687500 42.9958334, 141.4625000 42.9958334, 141.4625000 42.9916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral