public static int getNumDestinations(CodeBlock block, TaskMonitor monitor) throws CancelledException {
    	return getDestinations(block, null, monitor);
    }
Get number of destination references flowing out of this subroutine (block).
All Calls from this block, and all external FlowType block references
from this block are counted.

@param block code block to get the number of destination references from.
@param monitor task monitor
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/block/SubroutineDestReferenceIterator.java