Returns time when the L2A processing started and reports was created.
        :return: String in a form YYYYMMDDTHHMMSS
        :rtype: str

def get_report_time(self):
        """ Returns time when the L2A processing started and reports was created.
        :return: String in a form YYYYMMDDTHHMMSS
        :rtype: str
        """
        tree = get_xml(self.get_url(AwsConstants.REPORT))

        try:
            timestamp = tree.find('check/inspection').attrib['execution']
            return timestamp.split(',')[0].replace(' ', 'T').replace(':', '').replace('-', '')
        except AttributeError:
            warnings.warn('Could not obtain the L2A report creation time')
            return 'unknown'