メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.2375000 36.9208334, 138.2437500 36.9208334, 138.2437500 36.9250000, 138.2375000 36.9250000, 138.2375000 36.9208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral