メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.7625000 38.7416667, 139.7687500 38.7416667, 139.7687500 38.7458334, 139.7625000 38.7458334, 139.7625000 38.7416667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral