'return an opened file with the given mode.'

def open(self, mode='r'):

    if (mode not in ('r', 'rU')):
        raise ValueError(('mode    %r    not    supported' % (mode,)))
    assert self.check(file=1)
    if (self.rev is None):
        return self._svnpopenauth(('svn    cat    "%s"' % (self._escape(self.strpath),)))
    else:
        return self._svnpopenauth(('svn    cat    -r    %s    "%s"' % (self.rev, self._escape(self.strpath))))
