Function definition: Double down Complete the DoubleDown function to return twice the initialvalue. Function 8 \begin{tabular}{l|l} 1 & function finalvalue = Doubledown ( initialvalue) \\ 2 & \% Complete the function to return twice the initialvalue \\ 3 & finalvalue =0; \\ 4 & \\ 5 & end \\ 7 & \end{tabular}