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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 rgb_to_xterm(r, g, b):
 """Quantize RGB values to an xterm 256-color ID This works by envisioning the RGB values for all 256 xterm colors as 3D euclidean space and brute-force searching for the nearest neighbor. This is very slow. If you're very lucky, :func:`compile_speedup` will replace this function automatically with routines in `_xterm256.c`. """

    if r < 5 and g < 5 and b < 5:
        return 16
    best_match = 0
    smallest_distance = 10000000000
    for c in range(16, 256):
        d = (COLOR_TABLE[c][0] - r) ** 2 + \
            (COLOR_TABLE[c][1] - g) ** 2 + \
            (COLOR_TABLE[c][2] - b) ** 2
        if d < smallest_distance:
            smallest_distance = d
            best_match = c
    return best_match