@Beta
    public GetItemSpec withExpressionSpec(GetItemExpressionSpec xspec) {
        return withProjectionExpression(xspec.getProjectionExpression())
              .withNameMap(xspec.getNameMap())
              ;
    }
@ Beta public GetItemSpec withExpressionSpec ( GetItemExpressionSpec xspec ) { return withProjectionExpression ( xspec . getProjectionExpression ( ) ) . withNameMap ( xspec . getNameMap ( ) ) ; }
Convenient method to specify expressions (and the associated name map and
value map) via {@link GetItemExpressionSpec}.