メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.9187500 35.0708334, 138.9250000 35.0708334, 138.9250000 35.0750000, 138.9187500 35.0750000, 138.9187500 35.0708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral