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concat 

        # Array.concat

(from ruby core)
---
    array.concat(*other_arrays) -> self

---

Adds to `array` all elements from each Array in `other_arrays`; returns
`self`:
    a = [0, 1]
    a.concat([2, 3], [4, 5]) # => [0, 1, 2, 3, 4, 5]

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