@return [Integer] index of state requirement in reversed requirement tree
(the conflicting requirement itself will be at position 0)
Filter’s a state’s possibilities to remove any that would not satisfy the requirements in the conflict we’ve just rewound from @param [UnwindDetails] unwind_details details of the conflict just unwound from @return [void]
Filter’s a state’s possibilities to remove any that would (eventually) create a requirement in the conflict we’ve just rewound from @param [UnwindDetails] unwind_details details of the conflict just unwound from @return [void]
Attempts to update the existing vertex’s ‘PossibilitySet` with a filtered version @return [void]
Ensures any raised {NoSuchDependencyError} has its {NoSuchDependencyError#required_by} set. @yield