メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.6875000 42.6916667, 141.6937500 42.6916667, 141.6937500 42.6958334, 141.6875000 42.6958334, 141.6875000 42.6916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral