Debugging: Dasher Map (HashMap init / NullPointer / key swap bugs)

Problem: Debug the Dasher Map Module You are given code and unit tests (provided by the interviewer) for a Dasher real-time map module. The system is "randomly" failing. You must identify and fix the bugs so that all tests pass. Known symptoms (from the interview notes) Mis-configured HashMap initialization. NullPointer errors. Buggy key swapping causing inconsistent reads/writes. Your tasks Use logs/stack traces/failing tests to find root causes. Fix data structure initialization and null handling. Fix inconsistent key usage (e.g., lat/lng, dasherId/orderId, or map key/value swapped). Add at least 2 additional test cases that cover the fix and prevent regression. Output Briefly describe the fixes. Provide the key patched code snippets and the new tests (any language; pseudocode acceptable). Example Input UpdateLocation(dasherId=1, lat=37.7, lng=-122.4) then GetLocation(1) Output returns (37.7, -122.4) without exception