メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.3500000 44.4666667, 142.3562500 44.4666667, 142.3562500 44.4708334, 142.3500000 44.4708334, 142.3500000 44.4666667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral