code: @Override
    public Schema getById(MD5Digest id)
        throws IOException, SchemaRegistryException {
        if (_schemaHashMap.containsKey(id))
        {
          return _schemaHashMap.get(id);
        }
        else
        {
          throw new SchemaRegistryException("Could not find schema with id : " + id.asString());
        }
      }
docs: Get a schema given an id
  @param id
  @return
  @throws IOException
  @throws SchemaRegistryException