code: public void setRoleSelectionAllowed(boolean editRoles) {
  
          m_principalTypeSelect.removeItem(CmsRole.PRINCIPAL_ROLE);
          if (editRoles) {
              Item item = m_principalTypeSelect.addItem(CmsRole.PRINCIPAL_ROLE);
              String roleText = CmsVaadinUtils.getMessageText(org.opencms.workplace.commons.Messages.GUI_LABEL_ROLE_0);
              item.getItemProperty(CmsVaadinUtils.PROPERTY_LABEL).setValue(roleText);
          }
          m_principalTypeSelect.setNewItemsAllowed(!editRoles);
  
      }
docs: Enables/disables selection of the 'Roles' prinipal type.<p>
  
  @param editRoles true if the user should be allowed to select roles