code: def get_prefix():
    
  
    name = os.environ.get('NCLUSTER_PREFIX', DEFAULT_PREFIX)
    if name != DEFAULT_PREFIX:
      validate_prefix(name)
    return name
docs: Global prefix to identify ncluster created resources name used to identify ncluster created resources,
    (name of EFS, VPC, keypair prefixes), can be changed through $NCLUSTER_PREFIX for debugging purposes.