## Hidden elements

Any element can hidden in the UI by specifying the `ui_hidden = true`. All hidden elements must have a `default`.

### Example

```py
class Block:
    field: str = Field(default="hidden input",  # Default must be present if ui_hidden==True
                        title="title",
                        description="description",
                        json_schema_extra={SchemaKey.UI_ELEMENT: UIElement.STRING_INPUT,
                                            SchemaKey.UI_HIDDEN: True}
                        )
```
