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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 paragraph(node):
 """ Process a paragraph, which includes all content under it """

    text = ''
    if node.string_content is not None:
        text = node.string_content
    o = nodes.paragraph('', ' '.join(text))
    o.line = node.sourcepos[0][0]
    for n in MarkDown(node):
        o.append(n)

    return o