code: def _count_righthand_zero_bits(number, bits):
      
      if number == 0:
          return bits
      for i in range(bits):
          if (number >> i) & 1:
              return i
      # All bits of interest were zero, even if there are more in the number
      return bits
docs: Count the number of zero bits on the right hand side.
  
      Args:
          number: an integer.
          bits: maximum number of bits to count.
  
      Returns:
          The number of zero bits on the right hand side of the number.