code: function isFullSyncing( state, siteId ) {
  	const syncStatus = getSyncStatus( state, siteId );
  	if ( ! syncStatus ) {
  		return false;
  	}
  
  	const isStarted = get( syncStatus, 'started' );
  	const isFinished = get( syncStatus, 'finished' );
  
  	return isStarted && ! isFinished;
  }
docs: Returns a boolean for whether a site is in the process of a full sync.
  @param  {Object} state    Global state tree
  @param  {Number} siteId   Site ID
  @return {Boolean}         Whether a sync is in the process of syncing