メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.3812500 43.0500000, 141.3875000 43.0500000, 141.3875000 43.0541667, 141.3812500 43.0541667, 141.3812500 43.0500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral