@classmethod
def dump_str(cls, content, spaces=0):
    """
        Transforms a string to a string

        :param content: the string to transform
        :type content: ``str``

        :param spaces: shift to the right from containing elements
        :type spaces: ``int``

        :return: the related string

        """
    lines = content.split('\n')
    if len(lines) == 1:
        lines = content.split('\\n')
    if len(lines) == 1:
        if len(content) > 0 and content[-1] in ('-', '\\', '|'):
            return '"' + content + '"'
        return content
    text = '|'
    spaces += 2
    for line in lines:
        text += '\n'
        if len(line) > 0:
            text += ' ' * spaces + line
    return text
