# testing function "requiredBitNb"
#   requiredBitNb(1) = 1
#   requiredBitNb(2) = 2
#   requiredBitNb(3) = 2
# 
#   requiredBitNb(3) = 2
#   requiredBitNb(4) = 3
#   requiredBitNb(5) = 3
# 
#   requiredBitNb(7) = 3
#   requiredBitNb(8) = 4
#   requiredBitNb(9) = 4
# 
#   requiredBitNb(15) = 4
#   requiredBitNb(16) = 5
#   requiredBitNb(17) = 5
# 
#   requiredBitNb(31) = 5
#   requiredBitNb(32) = 6
#   requiredBitNb(33) = 6
# 
#   requiredBitNb(63) = 6
#   requiredBitNb(64) = 7
#   requiredBitNb(65) = 7
# 
#   requiredBitNb(127) = 7
#   requiredBitNb(128) = 8
#   requiredBitNb(129) = 8
# 
#   requiredBitNb(255) = 8
#   requiredBitNb(256) = 9
#   requiredBitNb(257) = 9
# 
#   requiredBitNb(511) = 9
#   requiredBitNb(512) = 10
#   requiredBitNb(513) = 10
# 
#   requiredBitNb(1023) = 10
#   requiredBitNb(1024) = 11
#   requiredBitNb(1025) = 11