メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.6812500 43.0250000, 141.6875000 43.0250000, 141.6875000 43.0291667, 141.6812500 43.0291667, 141.6812500 43.0250000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral