@Override
  public void validateStream(StreamSpec streamSpec) throws StreamValidationException {

  }
Validates the stream described by the streamSpec on the system.
A {@link StreamValidationException} should be thrown for any validation error.

@param streamSpec  The spec, or blueprint for the physical stream on the system.
@throws StreamValidationException if validation fails.
samza-core/src/main/java/org/apache/samza/system/inmemory/InMemorySystemAdmin.java