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