RangeSlider always_visible attribute cannot be set

Dash Python
1

hey guys,

am on dash 1.0.2 and I have a rangeslider on the page

            dcc.RangeSlider(
                id='filter-slider',
                min=0,
                max=20,
                step=1,
                value=[0, 20],
                marks={
                    0: '0%',
                    20: '20%'
                },
                tooltip={'placement': 'top', 'always_visible': True},
                className='universe-filter-item-component'
            )

based on rangeslider documentation, always_visible should be an attribute which i can set, however, when rendering the page i get

Failed component prop type: Invalid component prop tooltip key visible supplied to RangeSlider.
Bad object: {
“placement”: “top”,
“visible”: true
}
Valid keys: [
“always_visible”,
“placement”
]

looks like somewhere in dash, the prop attribute ‘always_visible’ has been changed to ‘visible’, anyone has similar issues?
thank you