6.2 printing definitions of internal functions

LaplaceTransform[x,x,t]; 
ClearAttributes[LaplaceTransform,ReadProtected] 
??LaplaceTransform
 

But better to use this:

Needs["GeneralUtilities`"]; 
PrintDefinitions@Charting`FindTicks
 

Thanks to https://mathematica.stackexchange.com/questions/132568/extract-ticks-from-plot

The above works if the function is not read protected.

See also this link