DFFML memory support default values TODO

default-values.patch

diff --git a/dffml/df/memory.py b/dffml/df/memory.py
index 7d29c84f..f6c7cdfb 100644
--- a/dffml/df/memory.py
+++ b/dffml/df/memory.py
@@ -586,8 +586,27 @@ class MemoryInputNetworkContext(BaseInputNetworkContext):
                                         ],
                                     )
                                 )
-                    # Return if there is no data for an input
+                    # There is no data in the network for an input
                     if not gather[input_name]:
+                        # Check if there is a default value for the parameter,
+                        # if so use it. That default will either come from the
+                        # definition attached to input_name, or it will come
+                        # from one of the alternate definition given within the
+                        # input flow for the input_name.
+                        # TODO
+                        to_check = [operation.inputs[input_name]] + alternate_defintions
+                        for check in to_check:
+                            if has default:
+                                gather[input_name].append(
+                                    Parameter(
+                                        key=input_name,
+                                        value=item.value,
+                                        origin=item,
+                                        definition=operation.inputs[input_name],
+                                    )
+                                )
+                        # If there is no default value, we don't have a complete
+                        # paremeter set, so we bail out
                         return
         # Generate all possible permutations of applicable inputs
         # Create the parameter set for each