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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 change_length(self, parameter, value):
 r"""Change the length of a certain parameter to a certain value. Args ---- parameter: str The name of the parameter to change the length for value: str The value to set the parameter to """


        self.preamble.append(UnsafeCommand('setlength',
                                           arguments=[parameter, value]))