#1703 Union | optional return types supported Pull request opened by kumare3 TL;DR Union types iterate through all variants to find the right fit. The incorrect fit should raise an error to prevent the wrong cast. Prior to the PR certain type transfomers (like None Type), tranform without considering if the python object is acceptable or matches the type. In the case of protobuf supported types like int, string, float etc, doing an implicit conversion will raise a runtime error, but for transformers like pickle or none type, this is leads to incorrect behavior. This is because, • none values can be pickled • none type in flyte is actually just an assignment and disregards the actual value. Type ☑︎ Bug Fix ☐ Feature ☐ Plugin Are all requirements met? ☑︎ Code completed ☑︎ Smoke tested ☑︎ Unit tests added ☑︎ Code documentation added ☑︎ Any pending items have an associated Issue This should fix the following fixes flyteorg/flyte#3319 flyteorg/flytekit ✅ All checks have passed 30/30 successful checks