メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.9625000 43.2708334, 141.9687500 43.2708334, 141.9687500 43.2750000, 141.9625000 43.2750000, 141.9625000 43.2708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral