private CodeBlock getSubFromCache(Address addr) {
		Object[] mapObjs = this.foundMSubs.getObjects(addr);
		return mapObjs.length == 0 ? null : (CodeBlock) mapObjs[0];
	}
Gets a subroutine from the cache containing addr.  If none there, returns null.
 It is assumed that an address will only occur within a single MSub
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/block/MultEntSubModel.java