FilterSpecByPaths removes unnecessary paths and definitions used by those paths.

FilterSpecByPathsWithoutSideEffects removes unnecessary paths and definitions used by those paths.

MergeSpecs copies paths and definitions from source to dest, rename definitions if needed.

MergeSpecsFailOnDefinitionConflict is differ from MergeSpecs as it fails if there is a definition conflict.

MergeSpecsIgnorePathConflict is the same as MergeSpecs except it will ignore any path conflicts by keeping the paths of destination.