struct pentry_state *pest)
const struct argp_state *state)
filter_doc (const char *doc, int key, const struct argp *argp,	    struct pentry_state *pest){  if (argp->help_filter)    /* We must apply a user filter to this output.  */    {      void *input = __argp_input (argp, pest->state);      return (*argp->help_filter) (key, doc, input);    }  else    /* No filter.  */    return (char *)doc;}