メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.0687500 43.5916667, 142.0750000 43.5916667, 142.0750000 43.5958334, 142.0687500 43.5958334, 142.0687500 43.5916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral