### Question:
IndentedCodeBlock extends SourceBlock { @Override public boolean canStart(LineSequence lineSequence) { Line line = lineSequence.getCurrentLine(); return line != null && PATTERN.matcher(line.getText()).matches(); }  @Override void process(ProcessingContext context, DocumentBuilder builder, LineSequence lineSequence); @Override boolean canStart(LineSequence lineSequence);  }### Answer:
@Test public void canStart() { assertFalse(block.canStart(LineSequence.create(" code"))); assertTrue(block.canStart(LineSequence.create(" code"))); assertTrue(block.canStart(LineSequence.create(" code"))); assertFalse(block.canStart(LineSequence.create(" code"))); assertFalse(block.canStart(LineSequence.create(" code"))); assertFalse(block.canStart(LineSequence.create("non-blank\n code"))); assertTrue(block.canStart(LineSequence.create("\tcode"))); assertTrue(block.canStart(LineSequence.create("\t code"))); assertTrue(block.canStart(LineSequence.create(" \tcode"))); assertTrue(block.canStart(LineSequence.create(" \tcode"))); assertTrue(block.canStart(LineSequence.create(" \tcode"))); }