メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.3937500 43.8291667, 142.4000000 43.8291667, 142.4000000 43.8333333, 142.3937500 43.8333333, 142.3937500 43.8291667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral