code: def _join_seq(d, k, v):
      '''Add a sequence value to env dict'''
  
      if k not in d:
          d[k] = list(v)
  
      elif isinstance(d[k], list):
          for item in v:
              if item not in d[k]:
                  d[k].insert(0, item)
  
      elif isinstance(d[k], string_types):
          v.append(d[k])
          d[k] = f _join_seq(d, k, v):
      '''Add a sequence value to env dict'''
  
      if k not in d:
          d[k] = list(v)
  
      elif isinstance(d[k], list):
          for item in v:
              if item not in d[k]:
                  d[k].insert(0, item)
  
      elif isinstance(d[k], string_types):
          v.append(d[k])
          d[k] = v
docs: Add a sequence value to env dict