#fixed code
                                public ColumnValue getAttribute(int encodedAttr) {
        int matchingColumn = integerToColumn.get(encodedAttr);

        String columnName = attributeDimensionNameMap.get(matchingColumn);
        Map<String, Integer> columnEncoding = integerEncoding.get(matchingColumn);
        String columnValue = null;
        for(Map.Entry<String, Integer> ce : columnEncoding.entrySet()) {
            if(ce.getValue() == encodedAttr) {
                columnValue = ce.getKey();
            }
        }

        return new ColumnValue(columnName, columnValue);
    }
#vulnerable code 
                                public ColumnValue getAttribute(int encodedAttr) {
        int matchingColumn = integerToColumn.get(encodedAttr);

        String columnName = attributeDimensionNameMap.get(matchingColumn);
        String columnValue = integerEncoding.get(matchingColumn).inverse().get(encodedAttr);

        return new ColumnValue(columnName, columnValue);
    } 
                            #location 5 
                            #vulnerability type NULL_DEREFERENCE