EditorActionUtil.EXPECTED_CARET_OFFSET disappears in IDEA 15

Hi, what's the new way in IDEA 15 to get this data?  I'm currently using like this:

final Integer offset = editor.getUserData(EditorActionUtil.EXPECTED_CARET_OFFSET);
if (offset != null) {
   selectedPsiRuleNode = file.findElementAt(offset);
}
else {
   selectedPsiRuleNode = BaseRefactoringAction.getElementAtCaret(editor, file);
}

Can't find IDEA 15 open source. Any pointers? git shows only build 143 max.

thanks!
Ter