* <code>eval(String, ScriptContext)</code> is used.
     *
     * @param script A <code>String</code> containing the source of the script.
     *
     * @param bindings A <code>Bindings</code> to use as the <code>ENGINE_SCOPE</code>
     * while the script executes.
     *
     * @return The return value from <code>eval(String, ScriptContext)</code>
     * @throws ScriptException if an error occurs in script.
     * @throws NullPointerException if any of the parameters is null.
     */
    public Object eval(String script, Bindings bindings) throws ScriptException {
        
        ScriptContext ctxt = getScriptContext(bindings);
        
        return eval(script , ctxt);
    }
    
    /**
     * <code>eval(Reader)</code> calls the abstract
     * <code>eval(Reader, ScriptContext)</code> passing the value of the <code>context</code>
     * field.
     *
     * @param reader A <code>Reader</code> containing the source of the script.
     * @return The return value from <code>eval(Reader, ScriptContext)</code>
     * @throws ScriptException if an error occurs in script.
     * @throws NullPointerException if any of the parameters is null.
     */
    public Object eval(Reader reader) throws ScriptException {
        
        
        return eval(reader, context);
    }
    
    /**
     * Same as <code>eval(Reader)</code> except that the abstract
     * <code>eval(String, ScriptContext)</code> is used.
     *
     * @param script A <code>String</code> containing the source of the script.
     * @return The return value from <code>eval(String, ScriptContext)</code>
     * @throws ScriptException if an error occurrs in script.
     * @throws NullPointerException if any of the parameters is null.
     */
    public Object eval(String script) throws ScriptException {
        
        
        return eval(script, context);
    }
    
    /**
     * Returns a <code>SimpleScriptContext</code>.  The <code>SimpleScriptContext</code>:
     *<br><br>
     * <ul>
     * <li>Uses the specified <code>Bindings</code> for its <code>ENGINE_SCOPE</code>
     * </li>
     * <li>Uses the <code>Bindings</code> returned by the abstract <code>getGlobalScope</code>
     * method as its <code>GLOBAL_SCOPE</code>
     * </li>
     * <li>Uses the Reader and Writer in the default <code>ScriptContext</code> of this
     * <code>ScriptEngine</code>
     * </li>
     * </ul>
     * <br><br>
     * A <code>SimpleScriptContext</code> returned by this method is used to implement eval methods
     * using the abstract <code>eval(Reader,Bindings)</code> and <code>eval(String,Bindings)</code>
     * versions.
     *
     * @param nn Bindings to use for the <code>ENGINE_SCOPE</code>
     * @return The <code>SimpleScriptContext</code>
     */
    protected ScriptContext getScriptContext(Bindings nn) {
        
        SimpleScriptContext ctxt = new SimpleScriptContext();
        Bindings gs = getBindings(ScriptContext.GLOBAL_SCOPE);
        
        if (gs != null) {
            ctxt.setBindings(gs, ScriptContext.GLOBAL_SCOPE);
        }
        
        if (nn != null) {
            ctxt.setBindings(nn,
                    ScriptContext.ENGINE_SCOPE);
        } else {
            throw new NullPointerException("Engine scope Bindings may not be null.");
        }
        
        ctxt.setReader(context.getReader());
        ctxt.setWriter(context.getWriter());
        ctxt.setErrorWriter(context.getErrorWriter());
        
        return ctxt;
        
    }
}