module Diff
end

module Diff::LCS
  def self.LCS: (Array[String], Array[String]) -> Array[String]
              | (String, String) -> Array[String]
  def self.diff: (Array[String], Array[String]) -> Array[String]
              | (String, String) -> Array[String]

  def self.patch!: (Array[String], Array[String]) -> String
end