src/main/java/ognl/Ognl.java
public static void setRoot(Map context, Object root)
    {
        context.put(OgnlContext.ROOT_CONTEXT_KEY, root);
    }
public static void setRoot(Map context, Object root)
    {
        context.put(OgnlContext.ROOT_CONTEXT_KEY, root);
    }
Sets the root object to use for all expressions in the given context - doesn't necessarily replace
root object instances explicitly passed in to other expression resolving methods on this class.

@param context
The context to store the root object in.
@param root
The root object.