old_contents: """
  ===========
  RAG Merging
  ===========
  
  This example constructs a Region Adjacency Graph (RAG) and progressively merges
  regions which are similar in color. Merging two adjacent regions produces
  a new regions with all the pixels from the merged regions. Regions are merged
  till no two adjacent regions are similar enough.
  
  """
  
  from skimage import graph, data, io, segmentation, color
  
  
  img = data.coffee()
  labels = segmentation.slic(img, compactness=30, n_segments=400)
  g = graph.rag_mean_color(img, labels)
  labels2 = graph.merge_hierarchical(g, labels, 40)
  g2 = graph.rag_mean_color(img, labels2)
  
  out = color.label2rgb(labels2, img, kind='avg')
  out = segmentation.mark_boundaries(out, labels2, (0, 0, 0))
  io.imshow(out)
  io.show()
  
new_contents: """
  ===========
  RAG Merging
  ===========
  
  This example constructs a Region Adjacency Graph (RAG) and progressively merges
  regions which are similar in color. Merging two adjacent regions produces
  a new regions with all the pixels from the merged regions. Regions are merged
  till no two adjacent regions are similar enough.
  
  """
  
  from skimage import graph, data, io, segmentation, color
  
  
  img = data.coffee()
  labels = segmentation.slic(img, compactness=30, n_segments=400)
  g = graph.rag_mean_color(img, labels)
  labels2 = graph.merge_hierarchical(labels, g, 40)
  g2 = graph.rag_mean_color(img, labels2)
  
  out = color.label2rgb(labels2, img, kind='avg')
  out = segmentation.mark_boundaries(out, labels2, (0, 0, 0))
  io.imshow(out)
  io.show()
  
subject: fix example