Python's operator module contains two$-$argument functions such as add and sub for Python's built$-$in arithmetic operators. For example, add$(2,3)$ evalutes to $5,$ just like the expression $2+3.$

Fill in the blanks in the following function for adding a to the absolute value of b$,$ without calling abs$.$ You may not modify any of the provided code other than the two blanks.

def a$\_$plus$\_$abs$\_$b$($a$,$ b$)$:

$"""$Return a$+$abs$($b$),$ but without calling abs$.$

$>>>$ a$\_$plus$\_$abs$\_$b$(2,3)$

$5$

$>>>$ a$\_$plus$\_$abs$\_$b$(2,-3)$

$5$

$>>>$ a$\_$plus$\_$abs$\_$b$(-1,4)$

$3$

$>>>$ a$\_$plus$\_$abs$\_$b$(-1,-4)$

$3$

$"""$

if b $<0$:

f $=\_\_\_\_\_$

else:

f $=\_\_\_\_\_$

return f$($a$,$ b$)$