code: func seekCursor(cursor *bolt.Cursor, criteria []*Criterion) (key, value []byte) {
  	if len(criteria) != 1 {
  		return cursor.First()
  	}
  
  	if criteria[0].operator == gt || criteria[0].operator == ge || criteria[0].operator == eq {
  		seek, err := encode(criteria[0].value)
  		if err != nil {
  			return cursor.First()
  		}
  
  		return cursor.Seek(seek)
  	}
  
  	return cursor.First()
  }
docs: // seekCursor preps usually will simply set the cursor to the first k/v and return it,
  // however if there is only one critrion and it is either > = or >= then we can seek to the value and
  // save reads