void (@Nullable JdkComboBoxItem firstItem) { if (firstItem instanceof ProjectJdkComboBoxItem) { myModel.showProjectSdkItem(); } else if (firstItem instanceof NoneJdkComboBoxItem) { myModel.showNoneSdkItem(); } else if (firstItem instanceof ActualJdkComboBoxItem) { setSelectedJdk(((ActualJdkComboBoxItem)firstItem).myJdk); } }