メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.8625000 39.8166667, 141.8687500 39.8166667, 141.8687500 39.8208334, 141.8625000 39.8208334, 141.8625000 39.8166667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral