title: How to change input of a tensorflow.layers.dense() layer?
body: <p>In tensorflow layers.dense(inputs, units, activation) implements a Multi-Layer Perceptron layer with arbitrary activation function. 
  Say i defined my dense layer like this: </p>
  
  <pre><code>inputx = tf.placeholder(float, shape=[batch_size, input_size])
  dense_layer = tf.layers.dense(inputx, 128, tf.nn.relu)
  </code></pre>
  
  <p>Now later i want to feed it some other input, say after restoring it from a checkpoint or just merely in the same graph for some reason: </p>
  
  <pre><code>inputx_2 = tf.some_operation(whatever_thisdoes, shape = [batch_size_2, input_size])
  inputx = tf.placeholder(float, shape=[batch_size, input_size])
  dense_layer = tf.layers.dense(inputx, 128, tf.nn.relu)
  </code></pre>
  
  <p>How could i now get dense_layer and it's possibly already pretrained weights to apply to inputx_2? (Without assigning input_y the value of inputx_2 if possible?)
  Would having a different batch_size (batch_size_2 instead of batch_size) cause any trouble?</p>