@Test
@PrepareForTest(NetUtils.class)
public void configureNicGatewayAndManagementNetworkTestTrafficManagementAndIsValidCIDR() throws Exception {

    StringBuilder buf = new StringBuilder();
    PowerMockito.mockStatic(NetUtils.class);
    PowerMockito.doReturn(true).when(NetUtils.class, "isValidCIDR", Mockito.anyString());
    configureTestConfigureNicGatewayAndManagementNetwork(false, TrafficType.Management);
    spy.configureNicGatewayAndManagementNetwork(dest, buf, nic);
    Assert.assertEquals(" mgmtcidr=mgmt_cidr localgw=localgw", buf.toString());
}