code: def replace_markdown_cells(src, dst):
      
  
      # It is an error to attempt markdown replacement if src and dst
      # have different numbers of cells
      if len(src['cells']) != len(dst['cells']):
          raise ValueError('notebooks do not have the same number of cells')
  
      # Iterate over cells in src
      for n in range(len(src['cells'])):
          # It is an error to attempt markdown replacement if any
          # corresponding pair of cells have different type
          if src['cells'][n]['cell_type'] != dst['cells'][n]['cell_type']:
              raise ValueError('cell number %d of different type in src and dst')
          # If current src cell is a markdown cell, copy the src cell to
          # the dst cell
          if src['cells'][n]['cell_type'] == 'markdown':
              dst['cells'][n]['source'] = src['cells'][n]['source']
docs: Overwrite markdown cells in notebook object `dst` with corresponding
      cells in notebook object `src`.