code: def _line_wrapper(self,diffs):
          
  
          # pull from/to data and flags from mdiff iterator
          for fromdata,todata,flag in diffs:
              # check for context separators and pass them through
              if flag is None:
                  yield fromdata,todata,flag
                  continue
              (fromline,fromtext),(toline,totext) = fromdata,todata
              # for each from/to line split it at the wrap column to form
              # list of text lines.
              fromlist,tolist = [],[]
              self._split_line(fromlist,fromline,fromtext)
              self._split_line(tolist,toline,totext)
              # yield from/to line in pairs inserting blank lines as
              # necessary when one side has more wrapped lines
              while fromlist or tolist:
                  if fromlist:
                      fromdata = fromlist.pop(0)
                  else:
                      fromdata = ('',' ')
                  if tolist:
                      todata = tolist.pop(0)
                  else:
                      todata = ('',' ')
                  yield fromdata,todata,flag
docs: Returns iterator that splits (wraps) mdiff text lines