module RuboCop::Cop::Style::ConditionalAssignmentHelper

the actual `else` branch.
but the last `node` an `elsif` branch and consider the last `node`
to recursively iterate over all `else` branches and consider all
`elsif` branches show up in the `node` as an `else`. We need

def expand_elses(branch)
  elsif_branches = expand_elsif(branch)
  else_branch = elsif_branches.any? ? elsif_branches.pop : branch
  [elsif_branches, else_branch]
end