MATLAB: Where can I find documentation for the feature function

featurefeature memstatsMATLABmemstats

The function "feature" can be used to probe how much spare memory there is in a PC.
I want to use this function to probe how much spare memory there is, but I do NOT want it to print out the results to screen, I want it to simply access that information. Does anyone know how I can do that, or where the documentation for that function exists?
To get it to probe the memory stats, simply use the following:
feature('memstats')
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