question: return the first updatemsg in the msgqueue . concode_field_sep int bytesCount concode_elem_sep SortedMap<ChangeNumber,UpdateMsg> map concode_elem_sep Object lock concode_field_sep void add concode_elem_sep int bytesCount concode_elem_sep boolean contains concode_elem_sep UpdateMsg removeFirst concode_elem_sep int count concode_elem_sep boolean isEmpty concode_elem_sep void clear
target: UpdateMsg function ( ) { synchronized ( lock ) { return map . get ( map . firstKey ( ) ) ; } }