'Test the _write_fonts() method'

def test_write_fonts(self):

    xf_format = Format()
    xf_format.has_font = 1
    self.styles._set_style_properties([[xf_format], None, 1, 0, 0, 0, [], []])
    self.styles._write_fonts()
    exp = '<fonts    count="1"><font><sz    val="11"/><color    theme="1"/><name    val="Calibri"/><family    val="2"/><scheme    val="minor"/></font></fonts>'
    got = self.fh.getvalue()
    self.assertEqual(got, exp)
