question: public boolean hasCallEvent ( String channel , String from , String to ) { boolean hasEvent = false ; if ( mChannelCallMap . containsKey ( channel ) ) { P25CallEvent event = mChannelCallMap . get ( channel ) ; if ( to != null && event . getToID ( ) != null && to . contentEquals ( event . getToID ( ) ) ) { if ( from != null ) { if ( event . getFromID ( ) == null ) { hasEvent = true ; } else if ( from . contentEquals ( event . getFromID ( ) ) ) { hasEvent = true ; } } else { hasEvent = true ; } } } return hasEvent ; }
target:  Indicates if there a call event exists for the specified channel and from and to talkgroup identifiers.