メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.9937500 35.1708334, 139.0000000 35.1708334, 139.0000000 35.1750000, 138.9937500 35.1750000, 138.9937500 35.1708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral