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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 vizlib_binary_features(span1, span2):
 """ Visual-related features for a pair of spans """

    if same_page((span1, span2)):
        yield "SAME_PAGE", DEF_VALUE

        if is_horz_aligned((span1, span2)):
            yield "HORZ_ALIGNED", DEF_VALUE

        if is_vert_aligned((span1, span2)):
            yield "VERT_ALIGNED", DEF_VALUE

        if is_vert_aligned_left((span1, span2)):
            yield "VERT_ALIGNED_LEFT", DEF_VALUE

        if is_vert_aligned_right((span1, span2)):
            yield "VERT_ALIGNED_RIGHT", DEF_VALUE

        if is_vert_aligned_center((span1, span2)):
            yield "VERT_ALIGNED_CENTER", DEF_VALUE