### Question:
TransformLineSequence extends LineSequence { @Override public Line getNextLine() { Line line = delegate.getNextLine(); if (line != null) { line = transform.apply(line); } return line; } TransformLineSequence(LineSequence delegate, Function<Line, Line> transform); @Override Line getCurrentLine(); @Override Line getNextLine(); @Override void advance(); @Override LineSequence lookAhead();  }### Answer:
@Test public void getNextLine() { assertEquals("SECOND", lineSequence.getNextLine().getText()); lineSequence.advance(); assertNull(lineSequence.getNextLine()); }