### Question:
FilterParser { public static String filterToCql(final FilterType filter) throws CQLException, JAXBException { return CQL.write(filter); }  static FilterType cqlToFilter(final String cqlQuery); static String filterToCql(final FilterType filter); Object getQuery(final QueryConstraint constraint, final Map<String, QName> variables, final Map<String, String> prefixs, final List<QName> typeNames);  }### Answer:
@Test public void FiltertoCQLTest() throws Exception { ObjectFactory factory = new ObjectFactory(); final PropertyNameType propertyName = new PropertyNameType("ATTR1"); final LowerBoundaryType low = new LowerBoundaryType(); final LiteralType lowLit = new LiteralType("10"); low.setExpression(factory.createLiteral(lowLit)); final UpperBoundaryType upp = new UpperBoundaryType(); final LiteralType uppLit = new LiteralType("20"); upp.setExpression(factory.createLiteral(uppLit)); final PropertyIsBetweenType pib = new PropertyIsBetweenType(factory.createPropertyName(propertyName), low, upp); FilterType filter = new FilterType(pib); String result = FilterParser.filterToCql(filter); String expResult = ""; assertEquals(expResult, result); final LiteralType lit = new LiteralType("10"); final PropertyIsEqualToType pe = new PropertyIsEqualToType(lit, propertyName, Boolean.TRUE); filter = new FilterType(pe); result = FilterParser.filterToCql(filter); expResult = ""; assertEquals(expResult, result); }