public ConnectorHandle connectorHandle(String connectorName) {
        return connectorHandles.computeIfAbsent(connectorName, k -> new ConnectorHandle(connectorName));
    }
Get or create a connector handle for a given connector name. The connector need not be running at the time
this method is called. Once the connector is created, it will bind to this handle. Binding happens with the
connectorName.

@param connectorName the name of the connector
@return a non-null {@link ConnectorHandle}
connect/runtime/src/test/java/org/apache/kafka/connect/integration/RuntimeHandles.java