code: def _DecodeFixed64(buffer, pos):
      """Decode a fixed64."""
      new_pos = pos + 8
      return (struct.unpack("<Q", buffer[pos:new_pos])[0], new_pos)
  
imports: import math
  import struct
  from google.protobuf.internal import containers
  from google.protobuf.internal import encoder
  from google.protobuf.internal import wire_format
  from google.protobuf import message
label_desc: Use image node_id 18 for calling a global function with example usage: _DecodeFixed64(buffer, pos) and returns: struct,  new_pos