NoSuchMethodException while accessing "setIpAssignment" method of class WifiConfiguration

I am working from package name com.thinktube.adhocconfigdemo

Current class is AdHocConfigActivity which contains methods setStaticIpConfiguration.

The error while running app is as below.

com.thinktube.adhocconfigdemo W/System.err: java.lang.NoSuchMethodException: setIpAssignment [class android.net.IpConfiguration$IpAssignment]

com.thinktube.adhocconfigdemo W/System.err: at java.lang.Class.getMethod(Class.java:664)

com.thinktube.adhocconfigdemo W/System.err: at java.lang.Class.getDeclaredMethod(Class.java:626)

com.thinktube.adhocconfigdemo W/System.err: at com.thinktube.adhocconfigdemo.AdhocConfigActivity.callMethod(AdhocConfigActivity.java:213)

com.thinktube.adhocconfigdemo W/System.err: at com.thinktube.adhocconfigdemo.AdhocConfigActivity.setStaticIpConfiguration(AdhocConfigActivity.java:155

Here, 155th line of SetStaticIpConfigurationMethod is:

callMethod(config, "setIpAssignment", new String[] { "android.net.IpConfiguration$IpAssignment" }, new Object[] { ipAssignment });

and 213 line in my code is:

Method method = object.getClass().getDeclaredMethod(methodName, parameterClasses);

in callMethod method.

where callMethod is as below:

private static void callMethod(Object object, String methodName, String[] parameterTypes, Object[] parameterValues) throws ClassNotFoundException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, NoSuchMethodException
{
    Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
    for (int i = 0; i < parameterTypes.length; i++)
        parameterClasses[i] = Class.forName(parameterTypes[i]);

    Log.i("AdHocAct", parameterClasses[0].isEnum()+"");
    Log.i("AdHocAct", parameterClasses[0].getName());
    Log.i("AdHocAct", object.getClass().getName());
    Method method = object.getClass().getDeclaredMethod(methodName, parameterClasses);
    method.invoke(object, parameterValues);
}

Here, config object used to call callMethod method is of type WifiConfigurationNew class which extends WifiConfiguration class.

Logs printed in callMethod method are as below

com.thinktube.adhocconfigdemo I/AdHocAct: true

com.thinktube.adhocconfigdemo I/AdHocAct: android.net.IpConfiguration$IpAssignment

com.thinktube.adhocconfigdemo I/AdHocAct: com.thinktube.adhocconfigdemo.WifiConfigurationNew

My question is what is meaning of the error?

Is it says that method setIpAssignment with parameter type [class android.net.IpConfiguration$IpAssignment] does not exist?

Because, such a method is present in WifiConfiguration class. As below,

public void setIpAssignment(IpConfiguration.IpAssignment ipAssignment) {
    mIpConfiguration.ipAssignment = ipAssignment;
}