class Diff::LCS::ContextChange

def self.simplify(event)

are converted to '-' and '>' actions are converted to '+'.
Simplifies a context change for use in some diff callbacks. '<' actions 
def self.simplify(event)
  ea = event.to_a
  case ea[0]
  when '-'
    ea[2][1] = nil
  when '<'
    ea[0] = '-'
    ea[2][1] = nil
  when '+'
    ea[1][1] = nil
  when '>'
    ea[0] = '+'
    ea[1][1] = nil
  end
  Diff::LCS::ContextChange.from_a(ea)
end