code: def add_organization(db, organization):
      
      with db.connect() as session:
          try:
              add_organization_db(session, organization)
          except ValueError as e:
              raise InvalidValueError(e)
docs: Add an organization to the registry.
  
      This function adds an organization to the registry.
      It checks first whether the organization is already on the registry.
      When it is not found, the new organization is added. Otherwise,
      it raises a 'AlreadyExistsError' exception to notify that the organization
      already exists.
  
      :param db: database manager
      :param organization: name of the organization
  
      :raises InvalidValueError: raised when organization is None or an empty string
      :raises AlreadyExistsError: raised when the organization already exists
          in the registry.