6.9: Dropdowns Nested dropdowns example
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**Primary Actor**: User

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

**Goal**: Show user example with nested dropdowns

Main success scenario:
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1. User opens Dropdowns demo page
2. User clicks on Nested dropdowns sub-menu
3. User see clickable button "dropdown has nested submenu"
4. When user clicks on this button, then dropdown opened and there are 4 items, one of them is separated
5. When user move mouse to the first item with caret, then nested dropdown opened and there are 3 items in the sub-menu
6. When user move mouse to the second item with caret, then nested dropdown opened and there are 3 items in the sub-menu
7. When user clicks on button again, then dropdown closes

Variations:
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2*. User scroll to Nested dropdowns sub-menu