public Long getConstant(Varnode vnode, ContextEvaluator evaluator) {
		if (vnode == null) {
			return null;
		}

		if (!isConstant(vnode)) {
			if (evaluator == null) {
				return null;
			}

			// is there an assumed value that should be returned for any unknown value?
			Instruction instr = getCurrentInstruction(currentAddress);
			Long lval = evaluator.unknownValue(this, instr, vnode);
			if (lval != null) {
				return lval.longValue();
			}
			return null;
		}

		return vnode.getOffset();
	}
return the location that this varnode was last set
This is a transient thing, so it should only be used as a particular flow is being processed...

@param rvar the register varnode
@param bval this parameter is unused.
@return address that the register was set.
Ghidra/Features/Base/src/main/java/ghidra/program/util/VarnodeContext.java