code: func (db *TXDatabaseOverlay) GetFBlock(keymr string) (interfaces.IFBlock, error) {
  	h, err := primitives.NewShaHashFromStr(keymr)
  	if err != nil {
  		return nil, err
  	}
  
  	fBlock, err := db.DBO.FetchFBlock(h)
  	if err != nil {
  		return nil, err
  	}
  	return fBlock, nil
  }
docs: // GetFBlock retrives a Factoid Block from Factom