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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _GenerateSummary(self):
 """Generate a summary of the warnings and errors. Returns: The generated HTML as a string. """

    items = []
    if self._notices:
      items.append('notices: %d' % self._notice_count)
    if self._dataset_errors:
      items.append('errors: %d' % self._error_count)
    if self._dataset_warnings:
      items.append('warnings: %d' % self._warning_count)

    if items:
      return '<p><span class="fail">%s</span></p>' % '<br>'.join(items)
    else:
      return '<p><span class="pass">feeds merged successfully</span></p>'