@Override
	public SymbolIterator getDefinedSymbols() {
		RecordIterator it;
		try {
			it = adapter.getSymbols();
		}
		catch (IOException e) {
			program.dbError(e);
			it = new EmptyRecordIterator();
		}
		return new SymbolRecordIterator(it, true, true);
	}
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