code: def find_entry_name_of_alias(self, alias):
          
          if alias in self.aliases:
              name = self.aliases[alias]
              if name in self.entries:
                  return name
              else:
                  # Name wasn't found, possibly merged or deleted. Now look
                  # really hard.
                  for name, entry in self.entries.items():
                      aliases = entry.get_aliases(includename=False)
                      if alias in aliases:
                          if (ENTRY.DISTINCT_FROM not in entry or
                                  alias not in entry[ENTRY.DISTINCT_FROM]):
                              return name
  
          return None
docs: Return the first entry name with the given 'alias' included in its
          list of aliases.
  
          Returns
          -------
          name of matching entry (str) or 'None' if no matches