class_docstr: Gaussian head with fixed covariance.
  
  This module is intended to be attached to a neural network that outputs
  the mean of a Gaussian policy. Its covariance is fixed to a diagonal matrix
  with a given scale.
  
  Args:
      scale (float): Scale parameter.
code: def __init__(self, scale=1):
      super().__init__()
      self.scale = scale
  
file_path: pfrl/pfrl/policies/gaussian_policy.py
imports: import numpy
  import torch
  from torch import nn
label_desc: Use image node_id 1 to create a new GaussianHeadWithFixedCovariance object from inherited base classes: nn with example: obj = GaussianHeadWithFixedCovariance(scale)