Updates the properties of an existing GuidelinePageHeading. Requires basic:write scope to be accessible and Project permission level EDIT, or TRANSLATE when a language is given.
All mutations have exactly one input field called input with a unique input and return type. This is useful to write mutations with variables, so there is always one single variable per mutation. This makes it easier to use and reuse them.
The id of the GuidelinePageHeading that should be updated.
GuidelinePageHeading data.
The GuidelinePageHeading that was modified.