メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.4875000 38.1750000, 139.4937500 38.1750000, 139.4937500 38.1791667, 139.4875000 38.1791667, 139.4875000 38.1750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral