$6.$ In Programming Exercise $2,$ the class dateType was designed and

implemented to keep track of a date, but it has very limited operations.

Redefine the class dateType so that it can perform the following operations on a date, in addition to the operations already defined:

a$.$ Set the month.

b$.$ Set the day.

c$.$ Set the year.

d$.$ Return the month.

e$.$ Return the day.

f$.$ Return the year.

g$.$ Test whether the year is a leap year.

h$.$ Return the number of days in the month. For example, if the date is

$3-12-2019,$ the number of days to be returned is $31$ because there are

$31$ days in March.

i$.$ Return the number of days passed in the year. For example, if the date

is $3-18-2019,$ the number of days passed in the year is $77.$ Note that

the number of days returned also includes the current day.

j$.$ Return the number of days remaining in the year. For example, if the

date is $3-18-2019,$ the number of days remaining in the year is $288.$

k$.$ Calculate the new date by adding a fixed number of days to the date.

For example, if the date is $3-18-2019$ and the days to be added are $25,$

the new date is $4-12-2019.$