onBuildChanged: (handler: (build: Build_Contracts.Build): void): void. Required if reacting to the current build. More than one callbacks can be added, and all will be called. It is important to have atleast one call back, since that's how an extension can get information about the current build.
onViewDisplayed: (onDisplayedCallBack: (): void): void. Optional, If needed, this callback will be called when this particular extension is selected/displayed
selectTab: (tabId: string): void. Optional, for a given tab id, which can be contribution ID for tab or a well known tab id, the corresponding tab is selected if the tab is visible.