メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4875000 43.5291667, 142.4937500 43.5291667, 142.4937500 43.5333333, 142.4875000 43.5333333, 142.4875000 43.5291667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral