question: public void remove ( @ NonNull T item ) { int removeIndex ; synchronized ( lock ) { if ( items == null ) { return ; } removeIndex = items . indexOf ( item ) ; if ( removeIndex != - 1 ) { items . remove ( removeIndex ) ; } } if ( notifyOnChange && removeIndex != - 1 ) { notifyItemRemoved ( removeIndex ) ; } }
target:  Removes the specified item from the list