6.5: Dropdowns Trigger by isOpen property example
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**Primary Actor**: User

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

**Goal**: Show user example how to trigger dropdown by changing isOpen property

Main success scenario:
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1. User opens Dropdowns demo page
2. User clicks on Trigger by isOpen property sub-menu
3. User see 2 clickable buttons "Button dropdown" and "Toggle"
4. When user clicks on "Button dropdown", then dropdown opened and there are 3 items
5. When user clicks on any item, nothing happens
6. When user clicks on "Toggle", then dropdown closed
7. When user clicks on "Toggle" again, then dropdown opened and there are 3 items
8. When user clicks on "Toggle" again, then dropdown closed again
9. Template src should be implemented with dropdown.isOpen

Variations:
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2*. User scroll to Trigger by isOpen property sub-menu