code: func (c *Cursor) Reset(ps []Prefix) {
  	ps = newSortedPrefixes(ps, sortAscending, false)
  	if len(ps) > 0 {
  		c.ps = ps
  	}
  	c.set(0, c.ps[0].IP.To16())
  }
docs: // Reset resets all state and switches to ps.
  // It uses the existing prefixes when ps is nil.