public final Reference addInstructionXref(Address from, Address to, int opIndex,
			FlowType type) {
		return currentProgram.getReferenceManager()
				.addMemoryReference(from, to, type, SourceType.USER_DEFINED, opIndex);
	}
Adds a cross reference (XREF).
@param from     the source address of the reference
@param to       the destination address of the reference
@param opIndex  the operand index (-1 indicates the mnemonic)
@param type     the flow type
@return the newly created reference
@see ghidra.program.model.symbol.FlowType
@see ghidra.program.model.symbol.Reference
Ghidra/Features/Base/src/main/java/ghidra/program/flatapi/FlatProgramAPI.java