public void discardParameters() {
        parameters = new Values();
    }
Create a new empty set of parameters for this request. The old
set of parameters will still be valid, but will no longer be
part of this request. This method may be used to allow earlier
garbage collection of large parameters that are no longer
needed. While the obvious use of this method is to get rid of
parameters when being an RPC server it can also be used after
starting an RPC request on a client.
jrt/src/com/yahoo/jrt/Request.java