@Test
public void testRemediationFunctionConstantPerIssue() {

    remediation.func = "Constant issue";
    remediation.constantCost = "3 mn";
    DebtRemediationFunctions functions = mock(DebtRemediationFunctions.class);
    DebtRemediationFunction function = mock(DebtRemediationFunction.class);
    when(functions.constantPerIssue(eq(remediation.constantCost))).thenReturn(function);
    when(function.coefficient()).thenReturn("3 min");
    remediation.remediationFunction(functions);
    verify(functions).constantPerIssue("3 min");
    assertEquals("3 min",function.coefficient());
}