Introduce `ImmutableListFactory.ofNCopiesOf` method with implementation

[dmlloyd]

Partially addresses #1166; does not include primitive support yet

[dmlloyd]

Also I'm not quite sure where/how to add unit tests... this project is surprisingly complex. Any pointers are appreciated.

[prathasirisha]

Also I'm not quite sure where/how to add unit tests... this project is surprisingly complex. Any pointers are appreciated.

Hi @dmlloyd - Apologies for the late response. I took a quick look at your PR to help you with this question.

For the changes, you are making in ImmutableListFactoryImpl you will add tests in the module unit-tests and the class would be ListsTest.

For the changes you are making on the ImmutableNCopiesList, you will add a new test in

1. module unit-tests and package org.eclipse.collections.impl.list.immutable
2. module serialization-tests and same package as above org.eclipse.collections.impl.list.immutable Other test classes in this package will be a good starting point for your new test class.

Hope this helps. Please reach back, if you have any more questions. Thank you for your contribution!