A new hint has been added to replace explicit types with 'var', and vice versa, for JDK 10. This was described in
However the Hint is a Warning (lightbulb+yellow triangle) and is shown on every line that could be changed. This is not good because the hint is 'two-way' so even if you accept the fix it shows another warning suggesting to change it back. It should be just a lightbulb like the diamond inference hint, which only appears on the current line.