Collection 如何快速合并两组数据

```php
$arr = [
    [
        "time" => "2019-01"
        "total_price" => 20
        "name" => 1
    ],
    [
        "time" => "2019-01"
        "total_price" => 40
        "name" => 2
    ],
    [
        "time" => "2019-02"
        "total_price" => 30
        "name" => 1
    ],
    [
        "time" => "2019-02"
        "total_price" => 10
        "name" => 2
    ]
]

$arr_mix = [
    [
        "time" => "2019-01"
        "total_price" => 10
        "name" => 1
    ],
    [
        "time" => "2019-02"
        "total_price" => 20
        "name" => 2
    ]
]
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```php

$col = collect($arr);

$col_mix = collect($arr_mix);

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```php
 $col = $col->keyBy(function ($item) {
    return $item['time'] . '@' . $item['name'];
 });
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```php
$reduceTotalPrice = function (Collection $total, $item) {
    $identify = $item['time'] . '@' . $item['name'];
    if ($total->has($identify)) {
        $temp = $total->get($identify);
        data_set($temp, 'total_price', $temp['total_price'] + $item['total_price']);
    } else {
        $total->offsetSet($identify, $item);
    }
};

$col = $col_mix->reduce(function ($total, $item) use ($reduceTotalPrice) {
    $reduceTotalPrice($total, $item);
    return $total;
}, $colKey);

return $col->flatten();
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