12.1: Sortable basic example
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**Primary Actor**: User

**Scope**: Ngx-bootstrap DEMO / BS version 3&4

**Goal**: Show user basic sortable functionality

Main success scenario:
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1. User opens Sortable demo page
2. User clicks on Basic sub-menu
3. User see 2 bs-sortable components (the first contain 4 items and the second - 2) by default
4. Under each component user see code-preview block with appropriate models
5. When user moves item from the first sortable component to another, then this item appeared in the second component and model changed appropriate
6. When user moved all items from the first sortable component, then text "Drag here" shown and model is empty
7. When user moved all items from the second sortable component to the first, then text "Drag here" shown and second model is empty and first contains all 6 items

Variations:
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2*. User scroll to Basic sub-menu