fix incorrect getter

[jd-lara]

closes #1157

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.44%. Comparing base (fdde35f) to head (dc907c7).
Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1158   +/-   ##
=======================================
  Coverage   76.44%   76.44%           
=======================================
  Files         121      121           
  Lines       13082    13082           
=======================================
  Hits        10001    10001           
  Misses       3081     3081           

Flag	Coverage Δ
unittests	76.44% <100.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/devices_models/devices/thermal_generation.jl	84.60% <100.00%> (ø)

[github-actions]

Performance Results

Version	Precompile Time
Main	4.27894185
This Branch	4.874214857

Version	Build Time
Main-Build Time Precompile	60.969414802
Main-Build Time Postcompile	1.040114499
This Branch-Build Time Precompile	72.105397944
This Branch-Build Time Postcompile	1.017707404

Version	Solve Time
Main-Solve Time Precompile	700.118614043
Main-Solve Time Postcompile	671.951397296
This Branch-Solve Time Precompile	1373.5349967
This Branch-Solve Time Postcompile	1342.917263493