private CFGBuilder inlineLambda(PsiLambdaExpression lambda, Nullability resultNullability) {
    PsiElement body = lambda.getBody();
    PsiExpression expression = LambdaUtil.extractSingleExpressionFromBody(body);
    PsiType psiType = LambdaUtil.getFunctionalInterfaceReturnType(lambda);
    if (expression != null) {
      NullabilityProblemKind<PsiExpression> kind =
        resultNullability == Nullability.NOT_NULL ? NullabilityProblemKind.nullableFunctionReturn : NullabilityProblemKind.noProblem;
      myAnalyzer.addCustomNullabilityProblem(expression, kind);
      pushExpression(expression);
      myAnalyzer.removeCustomNullabilityProblem(expression);
      boxUnbox(expression, psiType);
    } else if(body instanceof PsiCodeBlock) {
      DfaVariableValue variable = createTempVariable(psiType);
      myAnalyzer.inlineBlock((PsiCodeBlock)body, resultNullability, variable, psiType);
      push(variable);
    } else {
      pushUnknown();
    }
    return this;
  }
private CFGBuilder inlineLambda(PsiLambdaExpression lambda, Nullability resultNullability)