code: def encode_uvarint(n, data):
      '''encodes integer into variable-length format into data.'''
      if n < 0:
          raise ValueError('only support positive integer')
      while True:
          this_byte = n & 127
          n >>= 7
          if n == 0:
              data.append(this_byte)
              break
          data.append(this_byte | 128f encode_uvarint(n, data):
      '''encodes integer into variable-length format into data.'''
      if n < 0:
          raise ValueError('only support positive integer')
      while True:
          this_byte = n & 127
          n >>= 7
          if n == 0:
              data.append(this_byte)
              break
          data.append(this_byte | 128)
docs: encodes integer into variable-length format into data.