public static boolean hasInboundFlowReferences(@Nonnull MethodNode method, @Nonnull List<AbstractInsnNode> block) {
		// No control flow instruction should point to this block *at all*.
		for (AbstractInsnNode insn : method.instructions) {
			// Skip instructions in the given block.
			if (block.contains(insn))
				continue;

			// Check for control-flow instructions pointing to a location in the given block.
			if (insn instanceof JumpInsnNode jump && block.contains(jump.label))
				return true;
			if (insn instanceof TableSwitchInsnNode tswitch) {
				if (block.contains(tswitch.dflt))
					return true;
				for (LabelNode label : tswitch.labels)
					if (block.contains(label))
						return true;
			}
			if (insn instanceof LookupSwitchInsnNode lswitch) {
				if (block.contains(lswitch.dflt))
					return true;
				for (LabelNode label : lswitch.labels)
					if (block.contains(label))
						return true;
			}
		}

		return false;
	}
Check if the given block of instructions is referenced by explicit control flow instructions.
<p/>
This does not cover the following cases:
<ul>
    <li>Linear control flow where the previous instruction continues normally to the next instruction.</li>
</ul>
This is checks for explicit control flow references such as:
<ul>
    <li>{@link JumpInsnNode}</li>
    <li>{@link TableSwitchInsnNode}</li>
    <li>{@link LookupSwitchInsnNode}</li>
</ul>

@param method
		Containing method to analyze control flow of.
@param block
		Some arbitrary list of instructions representing a block of code.

@return {@code true} when the method has control flow outside the given block that flows into the given block.
{@code false} when the given block is never explicitly flowed into via control flow instructions.
recaf-core/src/main/java/software/coley/recaf/util/AsmInsnUtil.java