メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((140.9062500 38.4958334, 140.9125000 38.4958334, 140.9125000 38.5000000, 140.9062500 38.5000000, 140.9062500 38.4958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral