code: public function removeTab($tabName, FormMapper $formMapper)
      {
          $tabs = $this->getFormTabs();
  
          if (array_key_exists($tabName, $tabs)) {
              $groups = $this->getFormGroups();
  
              if (!is_array($groups)) {
                  return;
              }
  
              foreach ($tabs[$tabName]['groups'] as $group) {
                  if (isset($groups[$group])) {
                      foreach ($groups[$group]['fields'] as $field) {
                          $formMapper->remove($field);
                      }
                  }
                  unset($groups[$group]);
              }
  
              $this->setFormGroups($groups);
              $this->removeEmptyGroups();
          }
      }
docs: Removes tab and all it's fields in it
  
  @param string $tabName
  @param FormMapper $formMapper