<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def generate(self, number=None):
 """Generates vectors from the Gaussian. @param number: optional, if given, generates more than one vector. @returns: generated vector(s), either as a one dimensional array (shape (d,)) if number is not set, or as a two dimensional array (shape (n, d)) if n is given as number parameter. """

        if number is None:
            return numpy.random.multivariate_normal(self.mu, self.sigma)
        else:
            return numpy.random.multivariate_normal(self.mu, self.sigma, number)