メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.8000000 37.6500000, 138.8062500 37.6500000, 138.8062500 37.6541667, 138.8000000 37.6541667, 138.8000000 37.6500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral