private static @Nullable PsiLambdaExpression getLambda(PsiMethodCallExpression call) {
    PsiExpression[] expressions = call.getArgumentList().getExpressions();
    if(expressions.length != 1) return null;
    PsiExpression expression = expressions[0];
    if(expression instanceof PsiLambdaExpression) return (PsiLambdaExpression)expression;
    if (expression instanceof PsiMethodReferenceExpression) {
      return LambdaRefactoringUtil
        .convertMethodReferenceToLambda((PsiMethodReferenceExpression)expression, false, true);
    }
    return null;
  }
private static @Nullable PsiLambdaExpression getLambda(PsiMethodCallExpression call)