code: private void buildFilterMenus() {
  		buildFilterSubMenu(firstNameFilterMenu, FIRST_NAME);
  		if (firstNameFilterMenu.getChildCount() == 0) {
  			firstNameFilterMenu.setVisible(false);
  		}
  
  		buildFilterSubMenu(lastNameFilterMenu, LAST_NAME);
  		if (lastNameFilterMenu.getChildCount() == 0) {
  			lastNameFilterMenu.setVisible(false);
  		}
  
  		buildFilterSubMenu(dobFilterMenu, DOB);
  		if (dobFilterMenu.getChildCount() == 0) {
  			dobFilterMenu.setVisible(false);
  		}
  	}
docs: Builds the menu content for each column heading's filter menu.