code: public void generateFromResources(TypeDef model, JavaFileObject fileObject, String resourceName) throws IOException {
          if (classExists(model)) {
              System.err.println("Skipping: " + model.getFullyQualifiedName()+ ". Class already exists.");
              return;
          }
          System.err.println("Generating: "+model.getFullyQualifiedName());
          new CodeGeneratorBuilder<TypeDef>()
                  .withContext(context)
                  .withModel(model)
                  .withWriter(fileObject.openWriter())
                  .withTemplateResource(resourceName)
                  .build()
                  .generate();
      }
docs: Generates a source file from the specified {@link io.sundr.codegen.model.TypeDef}.
  
  @param model        The model of the class to generate.
  @param fileObject   Where to save the generated class.
  @param resourceName The template to use.
  @throws IOException If it fails to create the source file.