synchronized void setFunction(Function function) {
			if (cachedFunction == function) {
				return;
			}

			clearCache();
			cachedFunction = function;
		}
Construct a reference iterator sorted on the from address.
@param set set of from addresses
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/references/ReferenceDBManager.java