class Diff::LCS::Change

def self.from_a(arr)
  arr = arr.flatten(1)
  case arr.size
  when 5
    Diff::LCS::ContextChange.new(*arr[0...5])
  when 3
    Diff::LCS::Change.new(*arr[0...3])
  else
    fail "Invalid change array format provided."
  end
end