メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.1812500 44.8833333, 142.1875000 44.8833333, 142.1875000 44.8875000, 142.1812500 44.8875000, 142.1812500 44.8833333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral