### Question:
StringsReplaceStepAnalyzer extends StepAnalyzer<ReplaceStringMeta> { @Override protected boolean isPassthrough( StepField originalFieldName ) { String[] inFields = baseStepMeta.getFieldInStream(); String origFieldName = originalFieldName.getFieldName(); for ( int i = 0; i < inFields.length; i++ ) { if ( inFields[i].equals( origFieldName ) && Const.isEmpty( baseStepMeta.getFieldOutStream()[i] ) ) { return false; } } return true; }  @Override Set<Class<? extends BaseStepMeta>> getSupportedSteps(); @Override Set<ComponentDerivationRecord> getChangeRecords( final ReplaceStringMeta stringsReplaceMeta );  }### Answer:
@Test public void testIsPassthrough() throws Exception { analyzer.setStepMeta( stringsReplaceMeta ); assertFalse( analyzer.isPassthrough( new StepField( "prev", "firstName" ) ) ); assertTrue( analyzer.isPassthrough( new StepField( "prev", "middleName" ) ) ); assertTrue( analyzer.isPassthrough( new StepField( "prev", "lastName" ) ) ); }