Eclipse has a behavior to suggest the list of methods that can be used with the class name or the instance variable of any class. This behavior works fine for few of the Java classes but for some other classes like DesiredCapabilities,etc., eclipse is not suggesting me the desired methods of this class.

Solution
The solution of the above issue is that we have to make some settings in our eclipse so that it should suggest all the methods of the class that we are using in our code. Select "Java Proposals" checkbox in Java Editor then save and refresh the project, the eclipse will start suggesting all the desired methods.

Follow the following steps to select the "Java Proposals" checkbox:

Window > Preferences > Java > Editor > Content Assist > Advanced > Java Proposals