メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.8250000 37.3750000, 138.8312500 37.3750000, 138.8312500 37.3791667, 138.8250000 37.3791667, 138.8250000 37.3750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral