メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.6000000 35.3500000, 138.6062500 35.3500000, 138.6062500 35.3541667, 138.6000000 35.3541667, 138.6000000 35.3500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral