public static boolean isFunctionalTypeMoreSpecificOnExpression(PsiType sType,
                                                                 PsiType tType,
                                                                 PsiExpression arg) {
    return isFunctionalTypeMoreSpecific(sType, tType, null, arg);
  }
public static boolean isFunctionalTypeMoreSpecificOnExpression(PsiType sType,
                                                                 PsiType tType,
                                                                 PsiExpression arg)