# Put real function
def convert(number):
   return 0 

phone_number = "123-456-7890"
formatted_number = convert(phone_number) 
print(formatted_number)

def test_convert():
    assert convert("123-456-7890") == "(123) 456 7890"
    assert convert("217-516-4564") == "(217) 516 4564"
    assert convert("123") == "Invalid number", "Invalid numbers are not proprly handled"