CallStateChangeReason
  
  Description:
  [ CCode ( cprefix = "TP_CALL_STATE_CHANGE_REASON_" ,  has_type_id = false ) ]
public enum CallStateChangeReason
  
  
             A simple representation of the reason for a change in the call's         state, which may be used by simple clients, or used as a
      fallback         when the DBus_Reason member of a Call_State_Reason         struct is not understood.
           
    Bitfield/set of flags generated from the Telepathy specification.
   
  
  
  Content:
  Enum values:
  
    - BUSY -          
         The CallState changed from             Initialised             Ended because the receiver is busy             (e.g. is already engaged in
        another call, and has not placed the             initiator in a call-waiting queue).
 
    - CONNECTIVITY_ERROR - 
                 It was not possible for the streaming implementation to connect             to any of the users
        participating in this call or content.
 
    - FORWARDED - 
                 The call was forwarded.
 
    - INTERNAL_ERROR - 
                 There has been an unexpected error in either the CM or some other             local component.
    
 
    - INVALID_CONTACT - 
                 The CallState changed because one             of the addresses does not exist on the network.
    
 
    - MEDIA_ERROR - 
                 Some aspect of the content is unsupported so has to be             removed from the call.
 
    - NETWORK_ERROR - 
                 There has been a network error related to the CM or the             signalling part of the call
        (compare and contrast:             Streaming_Error).
 
    - NO_ANSWER - 
                 The CallState changed from             Initialised or             Ended because the initiator        
            ended the call before the receiver accepted it.
 
    - PERMISSION_DENIED - 
                 The CallState changed because the           local user is not authorised.
 
    - PROGRESS_MADE - 
                 Situation normal.
 
    - REJECTED -  
                 The CallState changed from             Initialised or             Ended (or a content's direction             changed) because it was
        rejected by the remote user.
 
    - SERVICE_ERROR - 
                 There has been an unexpected error in the server or some other             remote component.
    
 
    - UNKNOWN -    
               We just don't know.
 
    - USER_REQUESTED - 
                 The change was requested by the contact indicated by the Actor             member of a
        Call_State_Reason struct.