code: def _accumulate(data_list, no_concat=()):
      
      acc = Accumulator()
      for data in data_list:
          for name, val in data.items():
              acc.add(name, val)
      out = {name: acc[name] for name in acc.names if name not in no_concat}
  
      # Some variables should not be concatenated but should be kept as lists.
      # This is when there can be several arrays of variable length (NumPy
      # doesn't support ragged arrays).
      out.update({name: acc.get(name) for name in no_concat})
      return out
docs: Concatenate a list of dicts `(name, array)`.
  
      You can specify some names which arrays should not be concatenated.
      This is necessary with lists of plots with different sizes.