メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.2187500 36.8375000, 138.2250000 36.8375000, 138.2250000 36.8416667, 138.2187500 36.8416667, 138.2187500 36.8375000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral