class CodeTranslator:
    def __init__(self):
        pass

    def translate_ast(self, source_code: str, source_lang: str, target_lang: str) -> str:
        """Mocks translating code strings."""
        if not source_code:
            raise ValueError("source_code cannot be empty")
        
        return f"Translated [{source_code}] from {source_lang} to {target_lang}"
