Sets or gets the gauge's properties for it's labels.
Possible Values:
'distance' - specifies the labels distance from the gauge's center. This value could be set in percents ('0%' - '100%') or using pixels. This property is with lower priority than the position property
'position' - specifies the gauge's labels position. Possible values for this property are 'inside', 'outside' and 'none' (if you want to use the distance property). If it's value is inside the labels are going to be shown inside the scale otherwise they will be shown outside. This property is with higher priority than the distance property
'interval' - specifies labels's frequency
'offset' - specifies labels's offset. This property is array with two elements. The first one is the left offset and the second one is the top offset
'style' - specifies the gauge's pointer style. Here you can set it's fill or stroke color
'formatValue' - callback used for formatting the label. This function accepts a single parameter which the user can format and return to the labels renderer
'visible' - indicates whether the labels will be visible