title: looking for source code of from gen_nn_ops in tensorflow
body: <p>I am new to tensorflow for deep learning and interested in deconvolution (convolution transpose) operation in tensorflow. I need to take a look at the source code for operating deconvolution. The function is I guess <a href="https://github.com/tensorflow/tensorflow/blob/master/tensorflow/python/ops/nn_ops.py#L1007" rel="noreferrer">conv2d_transpose() in nn_ops.py</a>.</p>
  
  <p>However, in the function it calls another function called <code>gen_nn_ops.conv2d_backprop_input()</code>. I need to take a look at what is inside this function, but I am unable to find it in the repository. Any help would be appreciated.</p>