メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.5625000 38.3125000, 139.5687500 38.3125000, 139.5687500 38.3166667, 139.5625000 38.3166667, 139.5625000 38.3125000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral