code: @Override
      public DBParameterGroup copyDBParameterGroup(CopyDBParameterGroupRequest request) {
          request = beforeClientExecution(request);
          return executeCopyDBParameterGroup(request);
      }
docs: <p>
  Copies the specified DB parameter group.
  </p>
  
  @param copyDBParameterGroupRequest
  @return Result of the CopyDBParameterGroup operation returned by the service.
  @throws DBParameterGroupNotFoundException
  <i>DBParameterGroupName</i> does not refer to an existing DB parameter group.
  @throws DBParameterGroupAlreadyExistsException
  A DB parameter group with the same name exists.
  @throws DBParameterGroupQuotaExceededException
  Request would result in user exceeding the allowed number of DB parameter groups.
  @sample AmazonNeptune.CopyDBParameterGroup
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/neptune-2014-10-31/CopyDBParameterGroup" target="_top">AWS
  API Documentation</a>