Plots the ELBO progress (if present)

def plot_elbo(self, figsize=(15,7)):
        """
        Plots the ELBO progress (if present)
        """
        import matplotlib.pyplot as plt

        plt.figure(figsize=figsize)
        plt.plot(self.elbo_records)
        plt.xlabel("Iterations")
        plt.ylabel("ELBO")
        plt.show()