-- Homework 25, problem 3: build this counter module.
--
-- Expose:
--   M.increment()  -- adds 1 to the counter
--   M.get()        -- returns the current value
--   M.reset()      -- sets the counter back to 0
--
-- The counter itself is a `local` variable declared at the TOP of
-- this file, outside the functions, so it persists across calls.

local M = {}

-- Your code goes here:


-- TODO: return M