The module class contains a function add_module 517 to initialize submodules. I am a bit confused what the purpose of this function is.
Most people initialize submodules as simple member variables of the supermodule (like in example 1). Is there any case where it is advantageous to initialize supmodules using the add_module 517 (as in example 2)? What is the recommended way of initializing submodules?
Is there any difference between example 1 and example 2?
Example 1: Initialize submodules as Member Variabels
class Net(nn.Module):
    def __init__(self):
	super(Net, self).__init__()
	self.conv1   = nn.Conv2d(3, 16, 5, padding=2)
	self.pool    = nn.MaxPool2d(2, 2)
	self.dropout = nn.Dropout2d(p=0.5)
	self.conv2   = nn.Conv2d(16, 16, 5, padding=2)
	self.conv3   = nn.Conv2d(16, 400, 11, padding=5)
	self.conv4   = nn.Conv2d(400, 200, 1)
	self.conv5   = nn.Conv2d(200, 1, 1)

Example 2: Initialize submodules using add_module
class Net(nn.Module):
    def __init__(self):
    super(Net, self).__init__()
    self.add_module("conv1", Conv2d(3, 16, 5, padding=2))
    self.add_module("pool", MaxPool2d(2, 2))
    self.add_module("dropout", Dropout2d(p=0.5))
    self.add_module("conv2", Conv2d(16, 16, 5, padding=2))
    self.add_module("conv3", Conv2d(16, 400, 11, padding=5))
    self.add_module("conv4", Conv2d(400, 200, 1))
    self.add_module("conv5", Conv2d(200, 1, 1))