@Override
		public Symbol next() {
			if (hasNext()) {
				try {
					return getSymbol(it.next());
				}
				catch (IOException e) {
					dbError(e);
				}
			}
			return null;
		}
Called by the NamespaceManager when a namespace is removed; remove all symbols that have the
given namespace ID.

@param namespaceID ID of namespace being removed
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/symbol/SymbolManager.java