メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.5625000 43.7875000, 142.5687500 43.7875000, 142.5687500 43.7916667, 142.5625000 43.7916667, 142.5625000 43.7875000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral