メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.0687500 37.1291667, 138.0750000 37.1291667, 138.0750000 37.1333333, 138.0687500 37.1333333, 138.0687500 37.1291667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral