I run Google PageSpeed Insights on my site, and it reports an issue that is "Avoid serving legacy JavaScript to modern browsers", as below: I have no idea of w
instrumentation
icloud-documents
roo
kotlinc
contingency
watson-iot
ecmascript-temporal
phantom-dsl
suite
timestamping
at-job
null-safety
external-process
uiwebview
doxygen
azure-form-recognizer
prologue
aws-dms
xcasset
gcc7
cover
bmake
event-b
icns
fiscal
keyboard-layout
componentmodel
colormatrixfilter
unstructured-loop
asyncsocket