public PsiElement getArgumentAnchor(int index) {
    if (myContext instanceof PsiCall) {
      PsiExpressionList argumentList = ((PsiCall)myContext).getArgumentList();
      if (argumentList != null) {
        return argumentList.getExpressions()[index];
      }
    }
    if (myContext instanceof PsiMethodReferenceExpression) {
      return ((PsiMethodReferenceExpression)myContext).getReferenceNameElement();
    }
    throw new AssertionError();
  }
public PsiElement getArgumentAnchor(int index)