How to use the react-redux-firebase.populate function in react-redux-firebase

({ firebase, firebase: { auth, data: { projects } } }, { params }) => ({
    auth,
    projects: populate(firebase, 'projects', populates)
  })
)

({ spotifyReducer,firebase, firebase: { auth, data: { projects } } }, { params }) => ({
		auth,
		projects: populate(firebase, 'projects', populates),
		spotifyReducer
	}),
	mapDispatchToProps,

connect(state => ({
    projects: populate(state.firebase, 'projects', populates)
  }))
)

const mapStateToProps = (state, ownProps) => ({
  uid: state.firebase.auth.uid,
  problemSolutions: (state.firebase.data.problemSolutions || {})[
    ownProps.match.params.problemId
  ],
  activity: (populate(state.firebase, "activities", populates) || {})[
    ownProps.match.params.problemId
  ],
  pathId: (
    (state.firebase.data.activities || {})[ownProps.match.params.problemId] ||
    {}
  ).path
});