code: def handle(cls, value, **kwargs):
          
  
          try:
              delimiter, text = value.split("::", 1)
          except ValueError:
              raise ValueError("Invalid value for split: %s. Must be in "
                               "<delimiter>::<text> format." % value)
  
          return text.split(delimiter)
docs: Split the supplied string on the given delimiter, providing a list.
  
          Format of value:
  
              <delimiter>::<value>
  
          For example:
  
              Subnets: ${split ,::subnet-1,subnet-2,subnet-3}
  
          Would result in the variable `Subnets` getting a list consisting of:
  
              ["subnet-1", "subnet-2", "subnet-3"]
  
          This is particularly useful when getting an output from another stack
          that contains a list. For example, the standard vpc blueprint outputs
          the list of Subnets it creates as a pair of Outputs (PublicSubnets,
          PrivateSubnets) that are comma separated, so you could use this in your
          config:
  
              Subnets: ${split ,::${output vpc::PrivateSubnets}}