Defines an action to take if project/resource with a given name already exists in the workspace.
Discard the generated content and keep the original or skip the generation step altogether.
Append the new content to the existing. For containers (directories) it means adding new resources next to the existing, which is semantically equivalent to merging.
Merge new and existing content, typically using a merger service for files. For projects and directories merge is equivalent to append.
Replace existing content with the new one. For containers (directories) it means deleting container elements before generation.