code: def validate_nodepool_name(namespace):
      
      if namespace.nodepool_name != "":
          if len(namespace.nodepool_name) > 12:
              raise CLIError('--nodepool-name can contain atmost 12 characters')
          if not namespace.nodepool_name.isalnum():
              raise CLIError('--nodepool-name should only contain alphanumeric characters')
docs: Validates a nodepool name to be at most 12 characters, alphanumeric only.