Receive a channel message

typedef struct vx_evt_message{    /**    * The common properties for all events    */    vx_evt_base_t base;    /**    * The handle returned from a successful SessionGroup create request.    * \see vx_req_sessiongroup_create    */    VX_HANDLE sessiongroup_handle;    /**    * The handle returned from successful Session add request.    * \see vx_req_sessiongroup_add_session    */    VX_HANDLE session_handle;    /**    * The URI of the sender of the message.    */    char *participant_uri;    /**    * The content type of the message.    */    char *message_header;    /**    * The contents of the message.    */    char *message_body;    /**    * The displayname if the participant_uri had a displayname.    */    char *participant_displayname;    /**    * The application of the entity who is sending the message.    * Can be NULL or empty.    */    char *application;    /**    * The identity that the original sender wants to present.    * This is different than the participant_uri, which is the actual internal Vivox identity of the original sender.    */    char *alias_username;    /**    * The encoded URI for the user with the tag.    * This uniquely identifies users that might appear multiple times in a channel    */    char *encoded_uri_with_tag;    /**    * The message is from the current signed in user.    */    int is_current_user;    /**    * The language (default NULL, implies "en").    */    char *language;    /**    * The namespace of the custom application stanza (optional, default NULL).    */    char *application_stanza_namespace;    /**    * The custom application stanza body (optional, default NULL).    */    char *application_stanza_body;}vx_evt_message_t;