def h3_to_geo_boundary(h3_index)
      geo_boundary = GeoBoundary.new
      Bindings::Private.h3_to_geo_boundary(h3_index, geo_boundary)
      geo_boundary[:verts].take(geo_boundary[:num_verts]).map do |d|
        [rads_to_degs(d[:lat]), rads_to_degs(d[:lon])]
      end
    end
def h3_to_geo_boundary(h3_index)
      geo_boundary = GeoBoundary.new
      Bindings::Private.h3_to_geo_boundary(h3_index, geo_boundary)
      geo_boundary[:verts].take(geo_boundary[:num_verts]).map do |d|
        [rads_to_degs(d[:lat]), rads_to_degs(d[:lon])]
      end
    end
Derive the geographical boundary as coordinates for a given H3 index.

 This will be a set of 6 coordinate pairs matching the vertexes of the
 hexagon represented by the given H3 index.

 If the H3 index is a pentagon, there will be only 5 coordinate pairs returned.

 @param [Integer] h3_index A valid H3 index.

 @example Derive the geographical boundary for the given H3 index.
   H3.h3_to_geo_boundary(617439284584775679)
   [
     [52.247260929171055, -1.736809158397472], [52.24625850761068, -1.7389279144996015],
     [52.244516619273476, -1.7384324668792375], [52.243777169245725, -1.7358184256304658],
     [52.24477956752282, -1.7336997597088104], [52.246521439109415, -1.7341950448552204]
   ]

 @return [Array<Array<Integer>>] An array of six coordinate pairs.