docs: private BigDecimal getTotalProjectIncome(BudgetContract budget) {
  		BigDecimal totalProjectIncome = BigDecimal.ZERO;
  		for (BudgetProjectIncomeContract budgetProjectIncome : budget
  				.getBudgetProjectIncomes()) {
  			totalProjectIncome = totalProjectIncome.add(budgetProjectIncome
  					.getProjectIncome().bigDecimalValue());
  		}
  		return totalProjectIncome;
  	}