-spec call(ConnHandle, ActionRequests, SendOptions) -> {ProtocolVersion, UserReply | [UserReply]}
              when
                  ConnHandle :: conn_handle(),
                  ActionRequests :: action_reqs() | [action_reqs()],
                  SendOptions :: [SendOption],
                  SendOption ::
                      {request_timer, megaco_timer()} |
                      {long_request_timer, megaco_timer()} |
                      {send_handle, send_handle()} |
                      {protocol_version, protocol_version()} |
                      {call_proxy_gc_timeout, non_neg_integer()},
                  ProtocolVersion :: protocol_version(),
                  UserReply :: Success | Failure,
                  Success :: {ok, Result} | {ok, Result, SuccessExtra},
                  Result :: MessageResult | SegmentResult,
                  MessageResult :: action_reps(),
                  SegmentResult :: SegmentsOk,
                  SegmentsOk :: [{segment_no(), action_reps()}],
                  Failure :: {error, Reason} | {error, Reason, ErrorExtra},
                  Reason :: MessageReason | SegmentReason | UserCancelReason | SendReason | OtherReason,
                  MessageReason :: error_desc(),
                  SegmentReason ::
                      {segment, SegmentsOk, SegmentsErr} |
                      {segment_timeout, MissingSegments, SegmentsOk, SegmentsErr},
                  SegmentsErr :: {segment_no(), error_desc()},
                  MissingSegments :: [segment_no()],
                  UserCancelReason :: {user_cancel, ReasonForUserCancel},
                  ReasonForUserCancel :: term(),
                  SendReason :: SendCancelledReason | SendFailedReason,
                  SendCancelledReason :: {send_message_cancelled, term()},
                  SendFailedReason :: {send_message_failed, term()},
                  OtherReason ::
                      {wrong_mid, WrongMid :: mid(), RightMid :: mid(), transaction_reply()} | term(),
                  SuccessExtra :: term(),
                  ErrorExtra :: term().

-spec cancel(ConnHandle, CancelReason) -> ok | {error, Reason}
                when ConnHandle :: conn_handle(), CancelReason :: term(), Reason :: term().

-spec cast(ConnHandle, ActionRequests, SendOptions) -> ok | {error, Reason}
              when
                  ConnHandle :: conn_handle(),
                  ActionRequests :: action_reqs() | [action_reqs()],
                  SendOptions :: [SendOption],
                  SendOption ::
                      {request_keep_alive_timeout, RequestKeepAliveTimer} |
                      {request_timer, megaco_timer()} |
                      {long_request_timer, megaco_timer()} |
                      {send_handle, send_handle()} |
                      {reply_data, ReplyData} |
                      {protocol_version, ProtocolVersion},
                  RequestKeepAliveTimer :: plain | non_neg_integer(),
                  ReplyData :: term(),
                  ProtocolVersion :: protocol_version(),
                  Reason :: term().

-spec conn_info(ConnHandle) -> [{Item, Value}]
                   when
                       ConnHandle :: conn_handle(),
                       Item :: requests | replies | conn_info_item(),
                       Value :: term().

-spec conn_info(ConnHandle, ConnInfo) -> Value
                   when
                       ConnHandle :: conn_handle(),
                       ConnInfo :: all | requests | replies | conn_info_item(),
                       Value :: term().

-spec connect(ReceiveHandle, RemoteMid, SendHandle, ControlPid) -> {ok, ConnHandle} | {error, Reason}
                 when
                     ReceiveHandle :: receive_handle(),
                     RemoteMid :: preliminary_mid | mid(),
                     SendHandle :: send_handle(),
                     ControlPid :: pid(),
                     ConnHandle :: conn_handle(),
                     Reason :: ConnectReason | HandleConnectReason | term(),
                     ConnectReason ::
                         {no_such_user, LocalMid} | {already_connected, ConnHandle} | term(),
                     LocalMid :: mid(),
                     HandleConnectReason :: {connection_refused, ConnData, ErrorInfo} | term(),
                     ConnData :: term(),
                     ErrorInfo :: term().

-spec connect(ReceiveHandle, RemoteMid, SendHandle, ControlPid, Extra) ->
                 {ok, ConnHandle} | {error, Reason}
                 when
                     ReceiveHandle :: receive_handle(),
                     RemoteMid :: preliminary_mid | mid(),
                     SendHandle :: send_handle(),
                     ControlPid :: pid(),
                     Extra :: term(),
                     ConnHandle :: conn_handle(),
                     Reason :: ConnectReason | HandleConnectReason | term(),
                     ConnectReason ::
                         {no_such_user, LocalMid} | {already_connected, ConnHandle} | term(),
                     LocalMid :: mid(),
                     HandleConnectReason :: {connection_refused, ConnData, ErrorInfo} | term(),
                     ConnData :: term(),
                     ErrorInfo :: term().

-spec decode_sdp(PP) -> {ok, SDP} | {error, Reason}
                    when
                        PP :: property_parm() | property_group() | property_groups() | asn1_NOVALUE,
                        SDP :: sdp() | DecodeSdpPropertyGroup | DecodeSdpPropertyGroups | asn1_NOVALUE,
                        DecodeSdpPropertyGroup :: [DecodeSDP],
                        DecodeSdpPropertyGroups :: [DecodeSdpPropertyGroup],
                        DecodeSDP :: sdp() | {property_parm(), DecodeError},
                        DecodeError :: term(),
                        Reason :: term().

-spec disable_trace() -> void().

-spec disconnect(ConnHandle, DiscoReason) -> ok | {error, ErrReason}
                    when ConnHandle :: conn_handle(), DiscoReason :: term(), ErrReason :: term().

-spec enable_trace(Level, Destination) -> void()
                      when
                          Level :: trace_level(),
                          Destination :: File | Port | HandlerSpec | io,
                          File :: string(),
                          Port :: integer(),
                          HandlerSpec :: {HandlerFun, InitialData},
                          HandlerFun :: trace_handler(),
                          InitialData :: trace_data().

-spec encode_actions(ConnHandle, ActionRequests, Options) -> {ok, Result} | {error, Reason}
                        when
                            ConnHandle :: conn_handle(),
                            ActionRequests :: action_reqs() | [action_reqs()],
                            Options :: [Option],
                            Option ::
                                {request_timer, megaco_timer()} |
                                {long_request_timer, megaco_timer()} |
                                {send_handle, send_handle()} |
                                {protocol_version, protocol_version()},
                            Result :: binary() | [binary()],
                            Reason :: term().

-spec encode_sdp(SDP) -> {ok, PP} | {error, Reason}
                    when
                        SDP ::
                            sdp_property_parm() |
                            sdp_property_group() |
                            sdp_property_groups() |
                            asn1_NOVALUE,
                        PP :: property_parm() | property_group() | property_groups() | asn1_NOVALUE,
                        Reason :: term().

-spec eval_digit_map(DigitMap) -> {ok, MatchResult} | {error, Reason}
                        when
                            DigitMap :: digit_map_value() | ParsedDigitMap,
                            ParsedDigitMap :: term(),
                            MatchResult :: {Kind, Letters} | {Kind, Letters, Extra},
                            Kind :: digit_map_kind(),
                            Letters :: [digit_map_letter()],
                            Extra :: digit_map_letter(),
                            Reason :: term().

-spec eval_digit_map(DigitMap, Timers) -> {ok, MatchResult} | {error, Reason}
                        when
                            DigitMap :: digit_map_value() | ParsedDigitMap,
                            ParsedDigitMap :: term(),
                            Timers :: Ignore | Reject,
                            Ignore :: ignore | {ignore, digit_map_value()},
                            Reject :: reject | {reject, digit_map_value()} | digit_map_value(),
                            MatchResult :: {Kind, Letters} | {Kind, Letters, Extra},
                            Kind :: digit_map_kind(),
                            Letters :: [digit_map_letter()],
                            Extra :: digit_map_letter(),
                            Reason :: term().

-spec get_stats() -> {ok, [TotalStats]} | {error, Reason}
                   when
                       TotalStats :: {conn_handle(), [Stats]} | {global_counter(), counter_value()},
                       Stats :: {counter(), counter_value()},
                       Reason :: term().

-spec get_stats(GCounter) -> {ok, Value} | {error, Reason}
                   when GCounter :: global_counter(), Value :: counter_value(), Reason :: term();
               (ConnHandle) -> {ok, [Stats]} | {error, Reason}
                   when
                       ConnHandle :: conn_handle(),
                       Stats :: {counter(), counter_value()},
                       Reason :: term().

-spec get_stats(ConnHandle, Counter) -> {ok, Value} | {error, Reason}
                   when
                       ConnHandle :: conn_handle(),
                       Counter :: counter(),
                       Value :: counter_value(),
                       Reason :: term().

-spec info() -> Info when Info :: [{Key, Value}], Key :: atom(), Value :: term().

-spec parse_digit_map(DigitMapBody) -> {ok, ParsedDigitMap} | {error, Reason}
                         when DigitMapBody :: string(), ParsedDigitMap :: term(), Reason :: term().

-spec print_version_info() -> void().

-spec print_version_info(Versions) -> void() when Versions :: [VersionInfo], VersionInfo :: term().

-spec process_received_message(ReceiveHandle, ControlPid, SendHandle, BinMsg) -> ok
                                  when
                                      ReceiveHandle :: receive_handle(),
                                      ControlPid :: pid(),
                                      SendHandle :: send_handle(),
                                      BinMsg :: binary().

-spec process_received_message(ReceiveHandle, ControlPid, SendHandle, BinMsg, Extra) -> ok
                                  when
                                      ReceiveHandle :: receive_handle(),
                                      ControlPid :: pid(),
                                      SendHandle :: send_handle(),
                                      BinMsg :: binary(),
                                      Extra :: term().

-spec receive_message(ReceiveHandle, ControlPid, SendHandle, BinMsg) -> ok
                         when
                             ReceiveHandle :: receive_handle(),
                             ControlPid :: pid(),
                             SendHandle :: send_handle(),
                             BinMsg :: binary().

-spec receive_message(ReceiveHandle, ControlPid, SendHandle, BinMsg, Extra) -> ok
                         when
                             ReceiveHandle :: receive_handle(),
                             ControlPid :: pid(),
                             SendHandle :: send_handle(),
                             BinMsg :: binary(),
                             Extra :: term().

-spec report_digit_event(DigitMapEvalPid, Events) -> ok | {error, Reason}
                            when
                                DigitMapEvalPid :: pid(),
                                Events :: digit_map_event() | [digit_map_event()],
                                Reason :: term().

-spec reset_stats() -> void().

-spec reset_stats(GCounter) -> void() when GCounter :: global_counter();
                 (ConnHandle) -> void() when ConnHandle :: conn_handle().

-spec set_trace(Level) -> void() when Level :: trace_level().

-spec start() -> ok | {error, Reason} when Reason :: term().

-spec start_user(UserMid, Config) -> ok | {error, Reason}
                    when
                        UserMid :: mid(),
                        Config :: [{Item, Value}],
                        Item :: user_info_item(),
                        Value :: term(),
                        Reason :: term().

-spec stop() -> ok | {error, Reason} when Reason :: term().

-spec stop_user(UserMid) -> ok | {error, Reason} when UserMid :: mid(), Reason :: term().

-spec system_info() -> [{Item, Value}] when Item :: system_info_item(), Value :: term().

-spec system_info(Item) -> Value when Item :: system_info_item(), Value :: term().

-spec test_digit_event(DigitMap, Events) -> {ok, Kind, Letters} | {error, Reason}
                          when
                              DigitMap :: digit_map_value() | ParsedDigitMap,
                              ParsedDigitMap :: term(),
                              Events :: digit_map_event() | [digit_map_event()],
                              Kind :: digit_map_kind(),
                              Letters :: [digit_map_letter()],
                              Reason :: term().

-spec test_reply(ConnHandle, Version, EncodingMod, EncodingConfig, Reply) -> {MegaMsg, EncodeRes}
                    when
                        ConnHandle :: conn_handle(),
                        Version :: protocol_version(),
                        EncodingMod :: module(),
                        EncodingConfig :: list(),
                        Reply :: error_desc() | [action_reply()],
                        MegaMsg :: megaco_message(),
                        EncodeRes :: {ok, Bin} | {error, Reason},
                        Bin :: binary(),
                        Reason :: term().

-spec test_request(ConnHandle, Version, EncodingMod, EncodingConfig, ActionRequests) ->
                      {MegaMsg, EncodeRes}
                      when
                          ConnHandle :: conn_handle(),
                          Version :: protocol_version(),
                          EncodingMod :: module(),
                          EncodingConfig :: list(),
                          ActionRequests :: action_reqs() | [action_reqs()],
                          MegaMsg :: megaco_message(),
                          EncodeRes :: {ok, Bin} | {error, Reason},
                          Bin :: binary(),
                          Reason :: term().

-spec token_tag2string(Tag) -> Result
                          when Tag :: atom(), Result :: string() | {error, Reason}, Reason :: term().

-spec token_tag2string(Tag, EncodingMod) -> Result
                          when
                              Tag :: atom(),
                              EncodingMod :: pretty | compact | module(),
                              Result :: string() | {error, Reason},
                              Reason :: term().

-spec token_tag2string(Tag, EncodingMod, Version) -> Result
                          when
                              Tag :: atom(),
                              EncodingMod :: pretty | compact | module(),
                              Version :: protocol_version() | v1 | v2 | v3,
                              Result :: string() | {error, Reason},
                              Reason :: term().

-spec update_conn_info(ConnHandle, Item, Value) -> ok | {error, Reason}
                          when
                              ConnHandle :: conn_handle(),
                              Item :: conn_info_item(),
                              Value :: term(),
                              Reason :: term().

-spec update_user_info(UserMid, Item, Value) -> ok | {error, Reason}
                          when
                              UserMid :: mid(),
                              Item :: user_info_item(),
                              Value :: term(),
                              Reason :: term().

-spec user_info(UserMid) -> [{Item, Value}]
                   when UserMid :: mid(), Item :: requests | replies | user_info_item(), Value :: term().

-spec user_info(UserMid, Input) -> Result
                   when
                       Input :: Requests | Replies | Item,
                       Requests :: requests,
                       Replies :: replies,
                       Item :: user_info_item(),
                       UserMid :: mid(),
                       Conn :: conn_handle(),
                       Result :: RequestsResult | RepliesResult | ItemResult,
                       RequestsResult :: [{Conn, [TransId]}],
                       ItemResult :: term(),
                       RepliesResult :: [{Conn, [{TransId, ReplyState, Handler}]}],
                       TransId :: transaction_id(),
                       ReplyState :: prepare | eval_request | waiting_for_ack | aborted,
                       Handler :: undefined | pid().

-spec versions1() -> {ok, VersionInfo} | {error, Reason} when VersionInfo :: list(), Reason :: term().

-spec versions2() -> {ok, VersionInfo} | {error, Reason} when VersionInfo :: list(), Reason :: term().