code: public SubReportBuilder setParameterMapPath(String path) {
  		subreport.setParametersExpression(path);
  		subreport.setParametersMapOrigin(DJConstants.SUBREPORT_PARAMETER_MAP_ORIGIN_PARAMETER);
  		return this;
  	}
docs: defines the KEY in the parent report parameters map where to get the subreport parameters map.
  @param path where to get the parameter map for the subrerpot.
  @return