メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.0750000 44.1875000, 143.0812500 44.1875000, 143.0812500 44.1916667, 143.0750000 44.1916667, 143.0750000 44.1875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral