title: CWPack - What is a "data" in cw_pack_context_init?
body: <p>I want to implement CWPack in my project, and I have hard time to understand it. If I understand it well, I have to make my variables to be cw_pack variables, and of course then make my functions and methods fit them. But I can't understand it here, where there is initiation of cw_pack object. </p>
  
  <p><code>int cw_pack_context_init (cw_pack_context* pack_context, void* data, unsigned long length, pack_overflow_handler hpo)</code></p>
  
  <p>As I know what void* is, i don't know what is the data I should give to this function. Anyone could help me or give some material to make me understand this by myself? Example from github in CWPack project doesn't help me.</p>