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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 get_scheduling_block(sub_array_id, block_id):
 """Return the list of scheduling blocks instances associated with the sub array"""

    block_ids = DB.get_sub_array_sbi_ids(sub_array_id)
    if block_id in block_ids:
        block = DB.get_block_details([block_id]).__next__()
        return block, HTTPStatus.OK

    return dict(error="unknown id"), HTTPStatus.NOT_FOUND