The bug

1. Any invalid value for [maskMode] in clone is treated as replace
   Ex. command (a block below you is moved to be next to you)

   /clone ~ ~-1 ~ ~ ~-1 ~ ~1 ~ ~ invalidValue move

2. Any invalid value for [cloneMode] in clone is treated as normal
   Ex. command (the command will fail with "Source and destination can not overlap", even thought invalidValue is not normal)

   /clone ~ ~ ~ ~1 ~ ~ ~ ~ ~ replace invalidValue

Expected behavior would be that is shows an error message that states that the argument is not valid