メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.3062500 42.3583333, 142.3125000 42.3583333, 142.3125000 42.3625000, 142.3062500 42.3625000, 142.3062500 42.3583333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral