code: def __init__(self, buf, ptr=0, endian=None):
      """Initialize unpacker
  
      Parameters
      ----------
      buf : buffer
         object implementing buffer protocol (e.g. str)
      ptr : int, optional
         offset at which to begin reads from `buf`
      endian : None or str, optional
         endian code to prepend to format, as for ``unpack`` endian
         codes.  None (the default) corresponds to the default
         behavior of ``struct`` - assuming system endian unless you
         specify the byte order specifically in the format string
         passed to ``unpack``
      """
      self.buf = buf
      self.ptr = ptr
      self.endian = endian
      self._cache = {}
  
imports: from struct import Struct
label_desc: Use image node_id 1 to create a new Unpacker object  with example: obj = Unpacker(buf, ptr, endian)