メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.7687500 39.8458334, 141.7750000 39.8458334, 141.7750000 39.8500000, 141.7687500 39.8500000, 141.7687500 39.8458334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral