code: func (h *Handler) Validate(chunk storage.Chunk) bool {
  	if len(chunk.Data()) < minimumSignedUpdateLength {
  		return false
  	}
  
  	// check if it is a properly formatted update chunk with
  	// valid signature and proof of ownership of the feed it is trying
  	// to update
  
  	// First, deserialize the chunk
  	var r Request
  	if err := r.fromChunk(chunk); err != nil {
  		log.Debug("Invalid feed update chunk", "addr", chunk.Address(), "err", err)
  		return false
  	}
  
  	// Verify signatures and that the signer actually owns the feed
  	// If it fails, it means either the signature is not valid, data is corrupted
  	// or someone is trying to update someone else's feed.
  	if err := r.Verify(); err != nil {
  		log.Debug("Invalid feed update signature", "err", err)
  		return false
  	}
  
  	return true
  }
docs: // Validate is a chunk validation method
  // If it looks like a feed update, the chunk address is checked against the userAddr of the update's signature
  // It implements the storage.ChunkValidator interface