Describe the Issue
In cleaning up the translator.py in flytekit, we started using Nones to act as the sentinel value to check for the existence of reference entities in dynamic tasks. This is not good.

This is assigned here:
https://github.com/flyteorg/flytekit/pull/481/files#diff-2abdf48adbfb3ca373dc812cebdf842d32aa74b15c72280bdaa83c5d0f39a280R359
and checked here:
https://github.co

Few remarks regarding the documentation were put into the git repository under:

• doc/source/missing.txt
• doc/source/remarks.txt

These files were removed in #178 and all issues from there are moved here.

doc/source/missing.txt:

Missing	

1. Missing explanation	
In 	
doc/source/tutorial.rst 	
    line 102 	
AND in 	
b2sdk/api.py 	
    line 194 	
there are mentions of "