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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 _CreateFolder(self, parent, name, visible=True, description=None):
 """Create a KML Folder element. Args: parent: The parent ElementTree.Element instance. name: The folder name as a string. visible: Whether the folder is initially visible or not. description: A description string or None. Returns: The folder ElementTree.Element instance. """

    folder = ET.SubElement(parent, 'Folder')
    name_tag = ET.SubElement(folder, 'name')
    name_tag.text = name
    if description is not None:
      desc_tag = ET.SubElement(folder, 'description')
      desc_tag.text = description
    if not visible:
      visibility = ET.SubElement(folder, 'visibility')
      visibility.text = '0'
    return folder