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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 calculate_vss(self, method=None):
 """ Calculate the vertical swimming speed of this behavior. Takes into account the vertical swimming speed and the variance. Parameters: method: "gaussian" (default) or "random" "random" (vss - variance) < X < (vss + variance) """

        if self.variance == float(0):
            return self.vss
        else:
            # Calculate gausian distribution and return
            if method == "gaussian" or method is None:
                return gauss(self.vss, self.variance)
            elif method == "random":
                return uniform(self.vss - self.variance, self.vss + self.variance)
            else:
                raise ValueError("Method of vss calculation not recognized, please use 'gaussian' or 'random'")