code: private BlockStmt fieldUpdaterGetAndSet(String fieldUpdaterFieldName, String newValueName) {
          BlockStmt body = new BlockStmt();
          body.addStatement(new ReturnStmt(
                  methodCallExpr(fieldUpdaterFieldName, "getAndSet", new ThisExpr(), new NameExpr(newValueName))));
          return body;
      }
docs: Generates something like
  <code>return P_INDEX_UPDATER.getAndSet(this, newValue)</code>
  
  @param fieldUpdaterFieldName
  @param newValueName
  @return