code: public <E> E get(PartitionKey key, GetModifier getModifier,
        EntityMapper<E> entityMapper) {
      byte[] keyBytes = entityMapper.getKeySerDe().serialize(key);
      Get get = new Get(keyBytes);
      HBaseUtils.addColumnsToGet(entityMapper.getRequiredColumns(), get);
      Result result = get(get, getModifier);
      if (result.isEmpty()) {
        return null;
      } else {
        return entityMapper.mapToEntity(result);
      }
    }
docs: Execute a Get on HBase, creating the Get from the key's toByteArray method.
  The returned Result of the Get will be mapped to an entity with the
  entityMapper, and that entity will be returned.
  
  If the getModifier is not null, it will be invoked before the created Get
  is executed.
  
  Any GetModifers registered with registerGetModifier will be invoked after
  the getModifier passed to this method is invoked, and before the Get is
  executed.
  
  @param key
  The StorageKey to create a Get from.
  @param getModifier
  Invoked before the Get to give callers a chance to modify the Get
  before it is executed.
  @param entityMapper
  The EntityMapper to use to map the Result to an entity to return.
  @return The entity created by the entityMapper.