def _fold(self, name, value, refold_binary=False):
        if hasattr(value, 'name'):
            return value.fold(policy=self)
        maxlen = self.max_line_length if self.max_line_length else float('inf')
        lines = value.splitlines()
        refold = (self.refold_source == 'all' or
                  self.refold_source == 'long' and
                    (lines and len(lines[0])+len(name)+2 > maxlen or
                     any(len(x) > maxlen for x in lines[1:])))
        if refold or refold_binary and _has_surrogates(value):
            return self.header_factory(name, ''.join(lines)).fold(policy=self)
        return name + ': ' + self.linesep.join(lines) + self.linesep
dataset/ETHPy150Open OpenCobolIDE/OpenCobolIDE/open_cobol_ide/extlibs/future/backports/email/policy.py/EmailPolicy._fold/original