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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 _get_dominant_angle(lines, domination_type=MEDIAN):
 """Picks dominant angle of a set of lines. Args: lines: iterable of (x1, y1, x2, y2) tuples that define lines. domination_type: either MEDIAN or MEAN. Returns: Dominant angle value in radians. Raises: ValueError: on unknown domination_type. """

    if domination_type == MEDIAN:
        return _get_median_angle(lines)
    elif domination_type == MEAN:
        return _get_mean_angle(lines)
    else:
        raise ValueError('Unknown domination type provided: %s' % (
            domination_type))