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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 html_body(input_string, source_path=None, destination_path=None, input_encoding='unicode', doctitle=1, initial_header_level=1):
 """ Given an input string, returns an HTML fragment as a string. The return value is the contents of the <body> element. Parameters (see `html_parts()` for the remainder):
 - `output_encoding`: The desired encoding of the output. If a Unicode string is desired, use the default value of "unicode" . """

    parts = html_parts(
        input_string=input_string, source_path=source_path,
        destination_path=destination_path,
        input_encoding=input_encoding, doctitle=doctitle,
        initial_header_level=initial_header_level)
    fragment = parts['html_body']
    return fragment