Describe the bug
Currently we can specify the formatting function only for ticks in the axis.
We need to somehow format the title for the tool-tip.

For Annotation we can do it by overriding header property like in example below

But I prefer to have common property like e.g. headerFormat for both cases
Describe the bug
Currently we can specify the formatting function only for ticks in the axis.
We need to somehow format the title for the tool-tip.

For Annotation we can do it by overriding header property like in example below

But I prefer to have common property like e.g.
headerFormatfor both cases