code: @Override
      public DeleteDBParameterGroupResult deleteDBParameterGroup(DeleteDBParameterGroupRequest request) {
          request = beforeClientExecution(request);
          return executeDeleteDBParameterGroup(request);
      }
docs: <p>
  Deletes a specified DBParameterGroup. The DBParameterGroup to be deleted can't be associated with any DB
  instances.
  </p>
  
  @param deleteDBParameterGroupRequest
  @return Result of the DeleteDBParameterGroup operation returned by the service.
  @throws InvalidDBParameterGroupStateException
  The DB parameter group is in use or is in an invalid state. If you are attempting to delete the parameter
  group, you cannot delete it when the parameter group is in this state.
  @throws DBParameterGroupNotFoundException
  <i>DBParameterGroupName</i> does not refer to an existing DB parameter group.
  @sample AmazonNeptune.DeleteDBParameterGroup
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/neptune-2014-10-31/DeleteDBParameterGroup" target="_top">AWS
  API Documentation</a>