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* State Transition
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This document highlights how actions, logic, and reducers interact
together to maintain this feature's state (a text document is used to
accommodate the wide free-format content).

Actions (see: actions.js)                        Logic (see: logic.js)                                          Reducer (see: state.js)
==============================================   ============================================================   ===============================
location

  > set current GPS location
 .setLocation(loc) ...........................................................................................  - location.loc = action.loc
