docs: def __parse_dois(self, x):
          """
          Parse the Dataset_DOI field. Could be one DOI string, or a list of DOIs
          :param any x: Str or List of DOI ids
          :return none: list is set to self
          """
          # datasetDOI is a string. parse, validate and return a list of DOIs
          if isinstance(x, str):
              # regex cleans string, and returns a list with 1 entry for each regex doi match
              m = clean_doi(x)
              # make sure m is not an empty list
              if m:
                  # set list directly into self
                  self.doi = m
  
          # datasetDOI is a list. use regex to validate each doi entry.
          elif isinstance(x, list):
              for entry in x:
                  # regex cleans string, and returns a list with 1 entry for each regex doi match
                  m = clean_doi(entry)
                  # make sure m is not an empty list
                  if m:
                      # combine lists with existing self list
                      self.doi += m
          return