@VisibleForTesting
    public void setColumnsDefineExpr(Map<String, Expr> columnNameToDefineExpr) {
        for (Map.Entry<String, Expr> entry : columnNameToDefineExpr.entrySet()) {
            for (Column column : schema) {
                if (column.getName().equalsIgnoreCase(entry.getKey())) {
                    column.setDefineExpr(entry.getValue());
                    break;
                }
            }
        }
    }
@Test
    public void testSetDefineExprCaseInsensitive() {
        List<Column> schema = Lists.newArrayList();
        Column column = new Column("UPPER", Type.ARRAY_VARCHAR);
        schema.add(column);
        MaterializedIndexMeta meta = new MaterializedIndexMeta(0, schema, 0, 0,
                (short) 0, TStorageType.COLUMN, KeysType.DUP_KEYS, null);

        Map<String, Expr> columnNameToDefineExpr = Maps.newHashMap();
        columnNameToDefineExpr.put("upper", new StringLiteral());
        meta.setColumnsDefineExpr(columnNameToDefineExpr);
        Assert.assertNotNull(column.getDefineExpr());
    }