protected boolean isKnown(DBTraceMemorySpace ms, long snap, CodeUnit cu) {
		if (ms == null) {
			return false;
		}
		AddressRange range = new AddressRangeImpl(cu.getMinAddress(), cu.getMaxAddress());
		var states = ms.getStates(snap, range);
		return TraceMemoryOperations.isStateEntirely(range, states, TraceMemoryState.KNOWN);
	}
Start adding the given block to the database

<p>
If this returns non-null, it should be immediately followed by
{@link InstructionBlockAdder#doAddInstructions()}.

@param lifespan the lifespan of each instruction
@param skipDelaySlots the addresses of delay-slotted instructions to skip
@param platform the instructions' platform (language, compiler)
@param block the block of instructions to add
@param overwrite true to overwrite existing defined units
@return the adder, or null
Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/trace/database/listing/DBTraceInstructionsView.java