Re: Object retval = (Object)bindings.get(var); // why not OK?

I'm wondering why I cannot simply cast the return result of .get() to
satisfy the compiler expectation that the method return an object.
Instead I have to assign the result of .get() to a variable and then
return that.

package redick;

import java.util.*;
import java.util.Iterator;

public class Environment {
        /*
         * map from a variable name to an Object - which may be a datum or a
         * procedure
         */
        public Map<String,Object> bindings = new HashMap<String, Object>();
        public Environment parent;

        public void put(String var, Object value) {
                bindings.put(var, value);
        }
        public Object get(String var) {

                Object retval = bindings.get(var); // cast not enough
                /* Cannot comment this section out */
                if (retval == null) {
                        return (Object)null;
                } else {
                        return retval;
                }
                /* End required section */
        }

        public String toString() { return bindings.toString(); }

}