MAP Data structure in Stellar to store key/value pairs

[Anil Donthireddy]

Hi,

I have gone through the stellar documentation to understand how to store 
key/value pairs in to an stellar object. I can see there are functions 
MAP_EXISTS() and MAP_GET() that do operations on key/value pairs.

But I am unable to find how to initialize MAP object and add/update key/value 
pairs in the MAP. Please help to store key/value pairs in stellar object.

Thanks,
Anil.