class RuboCop::Cop::Lint::RedundantRegexpQuantifiers

def each_redundantly_quantified_pair(node)
  seen = Set.new
  node.parsed_tree&.each_expression do |(expr)|
    next if seen.include?(expr) || !redundant_group?(expr) || !mergeable_quantifier(expr)
    expr.each_expression do |(subexp)|
      seen << subexp
      break unless redundantly_quantifiable?(subexp)
      yield(expr, subexp) if mergeable_quantifier(subexp)
    end
  end
end