default "" does not work on CDS variables in pipeline scripts

default "" does not work on CDS variables in pipeline scripts: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). I'm writing a step script in a CDS pipeline and I want to use a CDS application variable that may or may not be defined. According to the variables doc…