メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((144.6687500 43.8958334, 144.6750000 43.8958334, 144.6750000 43.9000000, 144.6687500 43.9000000, 144.6687500 43.8958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral