メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.6750000 42.6416667, 141.6812500 42.6416667, 141.6812500 42.6458334, 141.6750000 42.6458334, 141.6750000 42.6416667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral