メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.5812500 43.7916667, 141.5875000 43.7916667, 141.5875000 43.7958334, 141.5812500 43.7958334, 141.5812500 43.7916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral