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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_colors(self, prefix, len_):
 """Get the css color list"""


        def color(tupl):
            """Make a color css"""
            return ((
                '%s.color-{0}, %s.color-{0} a:visited {{\n'
                '  stroke: {1};\n'
                '  fill: {1};\n'
                '}}\n'
            ) % (prefix, prefix)).format(*tupl)

        def value_color(tupl):
            """Make a value color css"""
            return ((
                '%s .text-overlay .color-{0} text {{\n'
                '  fill: {1};\n'
                '}}\n'
            ) % (prefix, )).format(*tupl)

        def ci_color(tupl):
            """Make a value color css"""
            if not tupl[1]:
                return ''
            return (('%s .color-{0} .ci {{\n'
                     '  stroke: {1};\n'
                     '}}\n') % (prefix, )).format(*tupl)

        if len(self.colors) < len_:
            missing = len_ - len(self.colors)
            cycles = 1 + missing // len(self.colors)
            colors = []
            for i in range(0, cycles + 1):
                for color_ in self.colors:
                    colors.append(darken(color_, 33 * i / cycles))
                    if len(colors) >= len_:
                        break
                else:
                    continue
                break
        else:
            colors = self.colors[:len_]

        # Auto compute foreground value color when color is missing
        value_colors = []
        for i in range(len_):
            if i < len(self.value_colors) and self.value_colors[i] is not None:
                value_colors.append(self.value_colors[i])
            else:
                value_colors.append(
                    'white' if is_foreground_light(colors[i]) else 'black'
                )

        return '\n'.join(
            chain(
                map(color, enumerate(colors)),
                map(value_color, enumerate(value_colors)),
                map(ci_color, enumerate(self.ci_colors))
            )
        )