Usage of `formError` in `fieldToSelect`?

[tomibennett]

Hello,

When I use the component Select I have the following warning

Warning: React does not recognize the `formError` prop on a DOM element. \
If you intentionally want it to appear in the DOM as a custom attribute, \
spell it as lowercase `formerror` instead. If you accidentally passed it from a parent component,\
remove it from the DOM element.
    [...]

If I remove the property in FieldToSelect method, the warning disappear and I can still propagate error to fields. I can't see what is it used for. Hence the question, what is its usage and is it safe to delete?