code: def map_equal_contributions(contributors):
      
      equal_contribution_map = {}
      equal_contribution_keys = []
      for contributor in contributors:
          if contributor.get("references") and "equal-contrib" in contributor.get("references"):
              for key in contributor["references"]["equal-contrib"]:
                  if key not in equal_contribution_keys:
                      equal_contribution_keys.append(key)
      # Do a basic sort
      equal_contribution_keys = sorted(equal_contribution_keys)
      # Assign keys based on sorted values
      for i, equal_contribution_key in enumerate(equal_contribution_keys):
          equal_contribution_map[equal_contribution_key] = i+1
      return equal_contribution_map
docs: assign numeric values to each unique equal-contrib id