class RuboCop::Cop::Lint::DuplicateMatchPattern

def pattern_identity(pattern)
  pattern_source = if pattern.hash_pattern_type? || pattern.match_alt_type?
                     pattern.children.map(&:source).sort.to_s
                   else
                     pattern.source
                   end
  return pattern_source unless (guard = pattern.parent.children[1])
  pattern_source + guard.source
end