input: Write a function to format a 2D list into a JSON object.
  assert formatData2JSON([[1,2,3],[4,5,6],[7,8,9]]) == '[[1, 2, 3], [4, 5, 6], [7, 8, 9]]'
  assert formatData2JSON([[10,20,30],[40,50,60]]) == '[[10, 20, 30], [40, 50, 60]]'
  assert formatData2JSON([[1],[2],[3]]) == '[[1], [2], [3]]'
output: import json
  
  def formatData2JSON(data):
      return json.dumps(data)