I have one file of config which runs tests in one browser using capabilities.
Now I have created one more separate config file which contains multiCapabilites and will run same tests in multiple browsers.

I want to optimize configs so I second config file I write multiCapabilities for first config and used 

delete firstConfig['capabilities'];

to ignore the capabilities from first config and use all other params from firstConfig and use multiCapabilities from 2nd config and run.

Expected result:
params in configs should not be duplicated in both configs, only multiCapabilities is the change, rest of config is same.