code: def expand_role(self, role):
          
          if '/' in role:
              return role
          else:
              return self.boto_session.resource('iam').Role(role).arn
docs: Expand an IAM role name into an ARN.
  
          If the role is already in the form of an ARN, then the role is simply returned. Otherwise we retrieve the full
          ARN and return it.
  
          Args:
              role (str): An AWS IAM role (either name or full ARN).
  
          Returns:
              str: The corresponding AWS IAM role ARN.