メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.0187500 42.3916667, 141.0250000 42.3916667, 141.0250000 42.3958334, 141.0187500 42.3958334, 141.0187500 42.3916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral