overloaded$\_$add$($d$,$ key, value$)5$ pts Given a dictionary d$,$ a key, and a value, this function adds the key:value pair to the dictionary d$.$ If the key doesn$$t already exist in the dictionary, this function should simply add it$.$ However, if the key already exists, then rather than overriding the previous value, the dictionary should start keeping a list of values for that key, in the order they are added.

Preconditions and Postconditions

d: dict $->$ You cannot make any assumptions about the size or contents of d key: any immutable type value: any Returns: None

Examples:

$>>>$ my$\_$dict $=\{"$Alice$"$: "Engineer"$\}$

$>>>$ overloaded$\_$add$($my$\_$dict, "Bob", "Manager"$)$

$>>>$ my$\_$dict

$\{"$Alice$"$: "Engineer", "Bob": "Manager"$\}$

$>>>$ overloaded$\_$add$($my$\_$dict, "Alice", "Sales"$)$

$>>>$ my$\_$dict

$\{"$Alice$"$: $["$Engineer$",$ "Sales"$],$ "Bob": "Manager"$\}$

Recommended methods:

$$ type$()$ or isinstance$()$ methods

type$([5\mathrm{.}6])==$ list returns True

isinstance$([5\mathrm{.}6],$ list$)$ returns True

$$ list concatenation $(+)$ or append$()$

$$ def overloaded$\_$add$($d$,$ key, value$)$:

$"""$

$$ Adds the key value pair to the dictionary. If the key is already in the dictionary, the value is made a list and the new value is appended to it$.$

$>>>$ d $=\{"$Alice$"$: "Engineer"$\}$

$>>>$ overloaded$\_$add$($d$,$ "Bob", "Manager"$)$

$>>>$ overloaded$\_$add$($d$,$ "Alice", "Sales"$)$

$>>>$ d $==\{"$Alice$"$: $["$Engineer$",$ "Sales"$],$ "Bob": "Manager"$\}$

$$ True

$"""$

$$ #$-$ YOUR CODE STARTS HERE