Assume that max$2$ is a function that expects two integer parameters and returns the value of the larger one. Also assume that four variables, population$1,$ population$2,$ population $3,$ and population $4$ have already been defined and associated with integer values.

Write an expression $($not a statement!$)$ whose value is the largest of population$1,$ population$2,$ population $3,$ and population $4$ by calling max$2.$