@Override
			public void preMatchApply(MatchAction[] actions, Address addr) {
				contextValueList = null; // make sure, only context from these actions used
			}
Get an existing function right above the addr.
@param program program to check
@param addr address to check
@return true if there is an existing function above addr
Ghidra/Features/BytePatterns/src/main/java/ghidra/app/analyzers/FunctionStartAnalyzer.java