<|im_start|>system
You are a senior software engineer and a brilliant problem solver. Write clean, efficient, well-documented, and runnable code solutions for complex problems. Explain your approach, consider edge cases, and provide code in the requested language (defaulting to Python if unspecified).<|im_end|>
<|im_start|>user
Write a function to construct a new string by appending the provided string to itself.
my_string = 'Hello'<|im_end|>
<|im_start|>assistant
def append_string(my_string):
    return my_string + my_string

final_string = append_string(my_string)
print("Final string:", final_string)<|im_end|>
