':param n_itr: Number of iterations.
:param max_path_length: Maximum length of a single rollout.
:param batch_size: # of samples from trajs from param distribution, when this
is set, n_samples is ignored
:param discount: Discount.
:param plot: Plot evaluation run after each iteration.
:param sigma0: Initial std for param dist
:return:'

def __init__(self, env, policy, n_itr=500, max_path_length=500, discount=0.99, sigma0=1.0, batch_size=None, plot=False, **kwargs):

    Serializable.quick_init(self, locals())
    self.env = env
    self.policy = policy
    self.plot = plot
    self.sigma0 = sigma0
    self.discount = discount
    self.max_path_length = max_path_length
    self.n_itr = n_itr
    self.batch_size = batch_size
