メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.1562500 43.4416667, 142.1625000 43.4416667, 142.1625000 43.4458334, 142.1562500 43.4458334, 142.1562500 43.4416667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral