メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.7250000 42.2333333, 142.7312500 42.2333333, 142.7312500 42.2375000, 142.7250000 42.2375000, 142.7250000 42.2333333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral