class RuboCop::Cop::Lint::RedundantRegexpQuantifiers

def merged_quantifier(exp1, exp2)
  quantifier1 = mergeable_quantifier(exp1)
  quantifier2 = mergeable_quantifier(exp2)
  if quantifier1 == quantifier2
    # (?:a+)+ equals (?:a+) ; (?:a*)* equals (?:a*) ; # (?:a?)? equals (?:a?)
    quantifier1
  else
    # (?:a+)*, (?:a+)?, (?:a*)+, (?:a*)?, (?:a?)+, (?:a?)* - all equal (?:a*)
    '*'
  end
end