public AddressSetPropertyMap getOrCreatePotentialMatchPropertyMap(Program program) {
		if (potentialMatchAddressSetPropertyMap != null) {
			return potentialMatchAddressSetPropertyMap;
		}
		potentialMatchAddressSetPropertyMap =
			program.getAddressSetPropertyMap(PRE_FUNCTION_MATCH_PROPERTY_NAME);
		if (potentialMatchAddressSetPropertyMap != null) {
			return potentialMatchAddressSetPropertyMap;
		}

		try {
			potentialMatchAddressSetPropertyMap =
				program.createAddressSetPropertyMap(PRE_FUNCTION_MATCH_PROPERTY_NAME);
		}
		catch (DuplicateNameException e) {
			throw new AssertException(
				"Can't get DuplicateNameException since we tried to get it first");
		}

		return potentialMatchAddressSetPropertyMap;
	}
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