anchor.diff:  
   ###### interface
   let
  -  inherit (pkgs.lib) mkOption mkIf;
  +  inherit (pkgs.lib) mkOption mkIf optionalString stringAfter;
   
     options = {
       users = {
  
positive.code:     ];
    };
  
  }
  
negative.code:           ";
          };
  
          bind = {
            distinguishedName = mkOption {
              default = "";
              example = "cn=admin,dc=example,dc=com";
              type = with pkgs.lib.types; string;
              description = "
                The distinguished name to bind to the LDAP server with. If this
                is not specified, an anonymous bind will be done.
              ";
            };
  
            password = mkOption {
              default = "/etc/ldap/bind.password";
              type = with pkgs.lib.types; string;
              description = "
                The path to a file containing the credentials to use when binding
                to the LDAP server (if not binding anonymously).
              ";
            };
          };
  
        };
      };
    };
  