Strategy interface for getGeneratedNodePrivateKey()

[lucassaldanha]

There is a TODO on the test testGeneratedNodePrivateKeyThroughECKey on the class SystemPropertiesTest to create a strategy interface for getGeneratedNodePrivateKey().

/**
 * TODO: Consider using a strategy interface for #getGeneratedNodePrivateKey().
 * Anything 'File' and 'random' generation are difficult to test and assert
 */
@Test
public void testGeneratedNodePrivateKeyThroughECKey() throws Exception {
    ...
}

I'd love to get someone to review my PR and come with suggestions for improvements.

[mkalinin]

@lucassaldanha btw, did you finally create a PR? Sorry for late response

[lucassaldanha]

@mkalinin I had, but I closed it some time ago.

Anyway, I've opened a new one: #1104

Cheers!