public Set<FrequentSequenceItem> getForwardExtensionItems(Set<FrequentSequenceItem> locallyFrequentItems) {
		Set<FrequentSequenceItem> localExtensionItems = new HashSet<FrequentSequenceItem>();
		for (FrequentSequenceItem fItem : locallyFrequentItems) {
			if (fItem.getSupport() == support) {
				localExtensionItems.add(fItem);
			}
		}
		return localExtensionItems;
	}
Returns the subset of {@code locallyFrequentItems} which occur in all sequences in the
projected database
@param locallyFrequentItems {@code FrequentItem}s to check
@return {@code FrequentItem}s which occur in all sequence in projected database
Ghidra/Features/BytePatterns/src/main/java/ghidra/closedpatternmining/ProjectedDatabase.java