i got error on MultiView drill down (Warning: array_merge(): Expected parameter 1 to be an array, null given in D:\XAMPP\htdocs\koolreport\src\widgets\google\Chart.php on line 157),(Unspecified chart type.) in linechart

set up page

function setup()

{
       $this->src("mydata")->query("SELECT b.SubcategoryName as subcatname,SUM(a.quantity) as quantity,SUM(a.totalamount+a.TaxAmount) as amt FROM `salesitems` as a LEFT JOIN product_subcategory as b ON b.SubCategoryId = a.ProductsubCategoryId AND a.Appcode= b.AppCode WHERE a.AppCode= '$appCode' $saledate GROUP BY a.ProductsubCategoryId ORDER BY quantity desc")->pipe($this->dataStore("data"));
        
}

view page

<?php

use \koolreport\drilldown\MultiView;
use \koolreport\processes\CopyColumn;
use \koolreport\processes\DateTimeFormat;
use \koolreport\widgets\google\LineChart;
use \koolreport\widgets\google\ColumnChart;
use \koolreport\widgets\koolphp\Table;

$outletArray = $this->dataStore('data'); // all products ?> <div class="row">

<div class="col-md-12">
    <div class="tab-content px-1 pt-1">
        <div role="tabpanel" class="tab-pane fade active in" id="available" aria-labelledby="StocksTab" aria-expanded="true">
            <div class="table-responsive">
            <?php
                MultiView::create(array(
                    "name"=>"saleMultiView",
                    "dataSource"=>$this->dataStore('data'),
                    "title"=>"Sale By Month",
                    "views"=>array(
                        array(
                            "handler"=>"<i class='fa fa-line-chart'></i>",
                            "widget"=>array(LineChart::class,array(
                                "columns"=>array(
                                   
                                    "subcatname"=>array(
                                        "label"=>"Subcategory Name"
                                    ),
                                    "quantity"=>array(
                                        "label"=>"Order quantity"
                                    )
                                ),
                            ))
                        ),
                        array(
                            "handler"=>"<i class='fa fa-bar-chart'></i>",
                            "widget"=>array(ColumnChart::class,array(
                                "columns"=>array(
                                    "subcatname"=>array(
                                        "label"=>"Subcategory Name"
                                    ),
                                    "quantity"=>array(
                                        "label"=>"Order quantity"
                                    )
                                ),
                            ))
                        ),
                        array(
                            "handler"=>"<i class='fa fa-table'></i>",
                            "widget"=>array(Table::class,array(
                                "columns"=>array(
                                    
                                    "subcatname"=>array(
                                        "label"=>"Subcategory Name"
                                    ),
                                    "quantity"=>array(
                                        "label"=>"Order quantity"
                                    ),
                                    "amt"=>array(
                                        "label"=>"Total Amount"
                                    )
                                ),
                                "cssClass"=>array(
                                    "table"=>"table table-striped table-bordered"
                                ),
                                "options"=>array(
                        "paging"=>true,
                        "searching"=>true,
                        "order"=>array(
                            array(2,"desc")
                        ),
                        "responsive" => array(
                            "details" => "function() { 
                                $.fn.dataTable.Responsive.display.modal( {
                                    header: function ( row ) {
                                        var data = row.data();
                                        return 'Details for '+data[0]+' '+data[1];
                                    }
                                } ) 
                            }()",
                            "renderer" => "function() { 
                                $.fn.dataTable.Responsive.renderer.tableAll( {
                                    tableClass: 'table'
                                } )
                            }()",
                        )

                    ),
                            ))
                        ),
                    )
                ));
        ?> 
            
            </div>
        </div>
    </div>
</div>

</div>