メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.8250000 36.3500000, 138.8312500 36.3500000, 138.8312500 36.3541667, 138.8250000 36.3541667, 138.8250000 36.3500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral