code: def _return_fieldset(self, fieldset):
          
          collapsible = None
          description = None
          try:
              # Make sure strings with numbers work as well, do this
              int(str(fieldset))
              title = None
          except ValueError:
              if fieldset.count("|") > 1:
                  raise ImproperlyConfigured(
                      "The fieldset name does not "
                      "support more than one | sign. "
                      "It's meant to separate a "
                      "fieldset from its description."
                  )
  
              title = fieldset
              if "|" in fieldset:
                  title, description = fieldset.split("|")
              if fieldset and (fieldset[0] in "-+"):
                  if fieldset[0] == "-":
                      collapsible = "closed"
                  else:
                      collapsible = "open"
                  title = title[1:]
  
          return {
              "title": title,
              "description": description,
              "collapsible": collapsible,
          }
docs: This function became a bit messy, since it needs to deal with two
          cases.
  
          1) No fieldset, which is represented as an integer
          2) A fieldset