class_docstr: MLP encoder for MNIST.
class_docstr_tok: ["MLP","encoder","for","MNIST","."]
code: def _build(self, x):
      for size in self.layers:
          x = tf.nn.relu(snt.Linear(size)(x))
      pre_z = snt.Linear(2 * self.n_latent)(x)
      mu = pre_z[:, : self.n_latent]
      sigma = tf.nn.softplus(pre_z[:, self.n_latent :])
      return mu, sigma
  
imports: import numpy
  import sonnet
  import tensorflow.compat.v1
label_desc: Use image node_id 2 for calling the EncoderMNIST obj's underlying member method code with example usage: obj._build(x) and returns: mu,  sigma