def __init__(self):
    """Initializes with an empty list of diffs.
    """
    self.diffs = []
    self.start1 = None
    self.start2 = None
    self.length1 = 0
    self.length2 = 0
def __init__ ( self ) : self . diffs = [ ] self . start1 = None self . start2 = None self . length1 = 0 self . length2 = 0
Initializes with an empty list of diffs.