code: def _get_maxval(size, signed=True):
      if signed and size == 1:
          return 0x7F
      elif size == 1:
          return 0xFF
      elif signed and size == 2:
          return 0x7FFF
      elif size == 2:
          return 0xFFFF
      elif signed and size == 4:
          return 0x7FFFFFFF
      elif size == 4:
          return 0xFFFFFFFF
  
imports: import math
  import struct
  from ctypes import create_string_buffer
label_desc: Use image node_id 8 for calling a global function with example usage: _get_maxval(size, signed) and returns: int, int, int, int, int, int