メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.3812500 44.3000000, 142.3875000 44.3000000, 142.3875000 44.3041667, 142.3812500 44.3041667, 142.3812500 44.3000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral