However, withdrawal from caffeine is seldom dangerous, though it can make one uncomfortable for a few days. The most frequent symptom associated with this withdrawal is a moderate to severe headache. This can occur between 12 and 24 hours after last intake of caffeine.
Okay, for step one you need to get the command blocks in your inventory. Make sure you have cheats ON and say /give (player name) command_block. After you get in in your inventory place 5 in a row.
Dial star 60 (*60). You will receive instructions for call blocking, and you need to follow the prompts to add a new number to your block list, add the last number that dialed you to your block list, remove a number from your block list, or edit/change a number on your block list.