メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.7312500 38.9958334, 141.7375000 38.9958334, 141.7375000 39.0000000, 141.7312500 39.0000000, 141.7312500 38.9958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral