/* Deserialization Tests Begin */
    @Test
    public void invalidMessageType() throws KVException{
    	sock = setupSocket("invalidMessageType.txt");
    	KVMessage kvm = new KVMessage("wrong_type");
    	assertNotNull(kvm);
    	try{
    		kvm.sendMessage(sock);
    	} catch(KVException e){
    		assertEquals(ERROR_INVALID_FORMAT, e.getKVMessage().getMessage());
    	}
    }

I'm trying to make the output stream atm.
private Socket setupOutputSocket(String filename) {
        sock = mock(Socket.class);
        File f = new File(System.getProperty("user.dir"), TEST_INPUT_DIR + filename);
        try {
            doNothing().when(sock).setSoTimeout(anyInt());
            when(sock.getOutputStream()).thenAnswer(new FileInputStream(f));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return sock;
    }