code: func (msg *MsgAddr) MaxPayloadLength(pver uint32) uint32 {
  	if pver < MultipleAddressVersion {
  		// Num addresses (varInt) + a single net addresses.
  		return MaxVarIntPayload + maxNetAddressPayload(pver)
  	}
  
  	// Num addresses (varInt) + max allowed addresses.
  	return MaxVarIntPayload + (MaxAddrPerMsg * maxNetAddressPayload(pver))
  }
docs: // MaxPayloadLength returns the maximum length the payload can be for the
  // receiver.  This is part of the Message interface implementation.