Plugin Development for CLion: How to add a method call to an existing method

Hi,

I am currently learning about how to write plugins for IntelliJ IDEs. I am especially interested in writing plugins for CLion.
I am trying to find a way how to add a method call to the top of the body of an existing method.
I already found a way to get the Function Definitions  in a File.

psiFile.accept(new PsiRecursiveElementWalkingVisitor(){
 @Override
 public void visitElement(PsiElement element) {
   super.visitElement(element);
   //OCFunctionDefinition test = new OCFunctionDefinition();
    if(element instanceof OCFunctionDefinition){
     infoBuilder.append(element.getText()).append("\n");
     element.add(elementAtCarret);
    }
  }
});

I read in the documentation that I can create new PsiFiles via PsiFileFactory.
For Java I could get a Factory with:

PsiElementFactory factory = JavaPsiFacade.getInstance(project).getElementFactory();

Is there also a Factry for c++? Something like:

PsiElementFactory factory = OcPsiFacade.getInstance(project).getElementFactory();

Also is this approach in general the right one, for adding a method call to an existing method body?