docs: public void initializeSerializerUnlessSet(ExecutionConfig executionConfig) {
  		if (serializer == null) {
  			checkState(typeInfo != null, "no serializer and no type info");
  
  			// instantiate the serializer
  			serializer = typeInfo.createSerializer(executionConfig);
  
  			// we can drop the type info now, no longer needed
  			typeInfo  = null;
  		}
  	}