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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 start_centroid_distance(item_a, item_b, max_value):
 """ Distance between the centroids of the first step in each object. Args: item_a: STObject from the first set in TrackMatcher item_b: STObject from the second set in TrackMatcher max_value: Maximum distance value used as scaling value and upper constraint. Returns: Distance value between 0 and 1. """

    start_a = item_a.center_of_mass(item_a.times[0])
    start_b = item_b.center_of_mass(item_b.times[0])
    start_distance = np.sqrt((start_a[0] - start_b[0]) ** 2 + (start_a[1] - start_b[1]) ** 2)
    return np.minimum(start_distance, max_value) / float(max_value)