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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def concatenate(self, others, axis=0):
 """Join a sequence of arrays along an existing axis. Parameters others : sequence of array_like The arrays must have the same shape, except in the dimension corresponding to `axis` (the first, by default). axis : int, optional The axis along which the arrays will be joined. Default is 0. Returns ------- res : ndarray The concatenated array. Examples -------- <HaplotypeArray shape=(6, 4) dtype=int8> 0 0 0 1 0 1 1 1 0 2 . . 0 0 0 1 0 1 1 1 0 2 . . <HaplotypeArray shape=(3, 8) dtype=int8> 0 0 0 1 0 0 0 1 0 1 1 1 0 1 1 1 0 2 . . 0 2 . . """

        return concatenate_haplotype_array(self, others, axis=axis, cls=type(self),
                                           concatenate=np.concatenate)