Symbol sym = mRootSymbolTable.resolve(name);
if (null == sym) {
// Shouldn't happen; the type checker already accepted this statement.
throw new DAGOperatorException("No such object at top level: " + name);
}
EntityTarget targetType = dropNode.getType();
// Perform the operation.
mRootSymbolTable.remove(name);
mSubmitterSession.sendInfo("DROP " + targetType.toString().toUpperCase());
} else if (node instanceof NamedSourceNode) {
NamedSourceNode namedInput = (NamedSourceNode) node;
String streamName = namedInput.getStreamName();
Symbol symbol = mRootSymbolTable.resolve(streamName).resolveAliases();
if (null == symbol) {