Removes a possibility from ‘self` @return [PossibilityState] a state with a single possibility,
the possibility that was removed from `self`
Ensure argument is ‘mod_sequence_value’ or raise DataFormatError
Load extra data embed into binary format String object.
If value is an instance of class klass, return it, else create a new instance of klass with value value.
Processes the topmost available {RequirementState} on the stack @return [void]
@return [ResolutionState] the state whose ‘requirement` is the given
`requirement`.