public String getMessage() {
      return message;
    }
Preform some operation on the set of data for a category.
<p>
If <code>mergeExistingProperties</code> is <code>false</code>, the operation is to include the union of the existing and specified properties.
<p>
If <code>mergeExistingProperties</code> is <code>false</code>, the operation is to include only the specified properties.

@param categoryName            the category name
@param properties              a map of properties to set
@param mergeExistingProperties <code>true</code> to use the the set of existing properties along with the specified set of properties;
                               <code>false</code>  to use set of specified properties only
@param operation               the operation to perform
@param operationParameters     parameters to supply the name operation
@return an {@link OperationResult}
@throws SystemException if an error occurs while handling the request
ambari-server/src/main/java/org/apache/ambari/server/controller/internal/RootServiceComponentConfigurationHandler.java