SetExecutionMode.RdSets the execution settings of a workffow. Note, this is done
             by ajusting settings of the future package. This might
             affect calling programs. See package documentation/vignettes
             for info.
SetExecutionSettings(mode, moduleMaxMemorySize)
| mode | Execution mode. Must use a mode that is defined in UpDraft's constants.  | 
    
|---|---|
| moduleMaxMemorySize | Max memory a module can occupy without causing a runtime error. Value is assumed to be in Bytes.  | 
    
NULL