Documentation for writeVLong in WritableUtils states that "For
-112 <= i <= 127, only one byte is used"
Documentation for writeVInt states that "For -120 <= i <= 127, only one byte is used"
writeVInt calls internally writeVLong, so the ranges are the same for both functions.
After examining the code, I see that the documentation that is at writeVLong is correct.
Documentation for writeVInt is therefore incorrect and should be fixed.