code: public function addCompiler($compiler) {
          if($compiler instanceof CompilerFactoryInterface || $compiler instanceof CompilerInterface) {
              $this->compilers[] = $compiler;
              $this->orderedCompilers = NULL;
          } else
              throw new CompilerException("Can only add objects that implement CompilerInterface or CompilerFactoryInterface to context");
      }
docs: Makes a compiler ready to execute
  
  @param CompilerInterface|CompilerFactoryInterface $compiler