class_docstr: linear layer
class_docstr_tok: ["linear","layer"]
docstr: x shape: [batch, time, feat, channel]
  output shape: [batch, time, dim ]
code: def call(self, x, training):
      """x shape: [batch, time, feat, channel]
      output shape: [batch, time, dim ]
      """
      x = self.reshape1(x)
      x = self.fc(x)
      x = tf.nn.relu6(x)
      x = self.drop(x, training=training)
      # x = self.reshape2(x)
      return x
  
imports: import numpy
  from absl import logging
  import delta.compat
  from tensorflow.python.keras import backend
  from delta.models.base_model import Model
  from delta.layers.base_layer import Layer
  from delta import utils
  from delta.utils.register import registers
label_desc: Use image node_id 3 for calling the Linear obj's underlying member method code with example usage: obj.call(x, training) and returns: x