public int getExtrapop() {
		return extrapop;
	}
Returns the number of extra bytes popped from the stack when a function that uses
this model returns to its caller. This is usually just the number of bytes used to
store the return value, but some conventions may do additional clean up of stack parameters.
A special value of UNKNOWN_EXTRAPOP indicates that the number of bytes is unknown.  
@return the number of extra bytes popped
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/lang/PrototypeModel.java