@Test
 public void should_getStyledText_supportNull() throws Exception {
   final ContractConstraint constraint = ProcessFactory.eINSTANCE.createContractConstraint();
   constraint.setExpression(null);
   final StyledString styledText = labelProvider.getStyledText(constraint);
   assertThat(styledText.toString()).doesNotContain("\n").doesNotContain("\r");
 }
 @Test
 public void should_getStyledText_strip_expression_charriage() throws Exception {
   final ContractConstraint constraint = ProcessFactory.eINSTANCE.createContractConstraint();
   constraint.setExpression("toto == true && \n titi == false \r");
   final StyledString styledText = labelProvider.getStyledText(constraint);
   assertThat(styledText.toString()).doesNotContain("\n").doesNotContain("\r");
 }