メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((140.7937500 42.5208334, 140.8000000 42.5208334, 140.8000000 42.5250000, 140.7937500 42.5250000, 140.7937500 42.5208334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral