メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.4625000 38.3166667, 139.4687500 38.3166667, 139.4687500 38.3208334, 139.4625000 38.3208334, 139.4625000 38.3166667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral