メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((139.9750000 39.9000000, 139.9812500 39.9000000, 139.9812500 39.9041667, 139.9750000 39.9041667, 139.9750000 39.9000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral