def METHOD_NAME(oauth_params, body):
    """Prepare the Form-Encoded Body.
    Per `section 3.5.2`_ of the spec.
    .. _`section 3.5.2`: https://tools.ietf.org/html/rfc5849#section-3.5.2
    """
    # append OAuth params to the existing body
    return _append_params(oauth_params, body)