def METHOD_NAME(self):
    xml = (
        '''
        <article xmlns:xlink="http://www.w3.org/1999/xlink" article-type="research-article" xml:lang="en">
            <front>
                <article-meta>
                    <volume>56</volume>
                    <issue>4</issue>
                </article-meta>
            </front>
        </article>
        '''
    )
    xmltree = etree.fromstring(xml)
    expected = dict(
        object='volume',
        output_expected='56',
        output_obteined='56',
        match=True
    )
    obtained = IssueValidation(xmltree).validate_volume('56')
    self.assertDictEqual(expected, obtained)