static/admin/TinyMCETextArea.js
function (readOnly) {
        var me = this;

        var result = me.callParent(arguments);

        if (readOnly !== me.tinyMCEConfig.readonly) {
            me.reinitEditor({
                readonly: readOnly
            });

            me.syncEditorSize(me.lastWidth, me.lastHeight);
        }

        return result;
    }
function (readOnly) {
        var me = this;

        var result = me.callParent(arguments);

        if (readOnly !== me.tinyMCEConfig.readonly) {
            me.reinitEditor({
                readonly: readOnly
            });

            me.syncEditorSize(me.lastWidth, me.lastHeight);
        }

        return result;
    }
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