メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.4125000 43.0750000, 141.4187500 43.0750000, 141.4187500 43.0791667, 141.4125000 43.0791667, 141.4125000 43.0750000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral