メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((140.6937500 38.2333333, 140.7000000 38.2333333, 140.7000000 38.2375000, 140.6937500 38.2375000, 140.6937500 38.2333333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral