def METHOD_NAME():
    unreader = Unreader()
    unreader.chunk = mock.MagicMock(side_effect=[
        b'qwerty', b'asdfgh', b'zxcvbn', b'123456', b'', b''
    ])
    assert unreader.read(size=5) == b'qwert'
    assert unreader.read(size=5) == b'yasdf'
    assert unreader.read(size=5) == b'ghzxc'
    assert unreader.read(size=5) == b'vbn12'
    assert unreader.read(size=5) == b'3456'
    assert unreader.read(size=5) == b''