The given block is tested as a possible \b iblock. If this configuration works and is not a \b directsplit, \b true is returned. If the configuration works as a \b directsplit, then recursively check that its \b posta_block works as an \b iblock. If it does work, keep this \b iblock, otherwise revert to the \b directsplit configuration. In either case return \b true. Processing the \b directsplit
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