internal override void OnDropdownClosed()
        {
            m_PackageNamePlaceholder.OnDisable();
            m_PackageVersionPlaceholder.OnDisable();

            packageNameField.UnregisterCallback <ChangeEvent <string> >(OnTextFieldChange);
            packageNameField.UnregisterCallback <KeyDownEvent>(OnKeyDownShortcut);
            packageVersionField.UnregisterCallback <KeyDownEvent>(OnKeyDownShortcut);

            if (m_ExtraFetchOperation != null)
            {
                m_ExtraFetchOperation.onOperationError -= OnExtraFetchError;
                m_ExtraFetchOperation.onProcessResult  -= OnExtraFetchResult;
                m_ExtraFetchOperation.Cancel();
                m_ExtraFetchOperation = null;
            }

            if (m_AnchorWindow != null)
            {
                m_AnchorWindow.rootVisualElement.SetEnabled(true);
                m_AnchorWindow = null;
            }

            submitButton.clickable.clicked -= SubmitClicked;
        }
        internal override void OnDropdownClosed()
        {
            m_InputPlaceholder.OnDisable();

            inputTextField.UnregisterCallback <ChangeEvent <string> >(OnTextFieldChange);
            inputTextField.UnregisterCallback <KeyDownEvent>(OnKeyDownShortcut);

            submitButton.clickable.clicked -= SubmitClicked;

            if (m_AnchorWindow != null)
            {
                m_AnchorWindow.rootVisualElement.SetEnabled(true);
                m_AnchorWindow = null;
            }

            inputTextField.value = string.Empty;
            submitButton.text    = string.Empty;
            submitClicked        = null;
        }