code: def get_unique_ajps( benchmark_runs ):
          
          br_ajps = {}
          for br in benchmark_runs:
              for ajp in br.additional_join_parameters:
                  if ajp not in br_ajps:
                      br_ajps[ajp] = set()
                  br_ajps[ajp].add( br.additional_join_parameters[ajp]['short_name'] )
          unique_ajps = []
          for ajp in br_ajps:
              if len( br_ajps[ajp] ) > 1:
                  unique_ajps.append( ajp )
          return unique_ajps
docs: Determines which join parameters are unique