@Override
		public void apply(Program program, Address addr, Match match) {
			Listing listing = program.getListing();
			CodeUnit cu = listing.getCodeUnitContaining(addr);
			if (cu != null) {
				if (cu instanceof Data) {
					if (((Data) cu).isDefined()) {
						return;
					}
				}
				else {
					return;
				}
			}
			if (contextValueList == null) {
				contextValueList = new ArrayList<>();
			}
			Register contextReg = program.getProgramContext().getRegister(contextRegName);
			if (contextReg != null) {
				contextValueList.add(new RegisterValue(contextReg, value));
			}
		}
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