メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.9687500 37.2708334, 138.9750000 37.2708334, 138.9750000 37.2750000, 138.9687500 37.2750000, 138.9687500 37.2708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral