private boolean activeSources() {
		for (TaintLabel label : sources) {
			if (label.isActive())
				return true;
		}
		return false;
	}
Predicate indicating the presence of one or more sources in the source set;
this is used to determine state validity.

The source set MUST BE NON-EMPTY for a query to be executed.
Ghidra/Features/DecompilerDependent/src/main/java/ghidra/app/plugin/core/decompiler/taint/AbstractTaintState.java