@Override
			public boolean allowAccess(VarnodeContext context, Address addr) {
				// allow values to be read from writable memory
				return true;
			}
Check the current operand for references based on input/outputs

@param context - context holding values
@param instr - instruction under consideration
@param list - input/output lists
@param opIndex - index of operand to check

@return true if a reference was found
Ghidra/Features/Base/ghidra_scripts/MultiInstructionMemReference.java