docs: def startswith(self, prefix, ignore_case=False, options=None):
          """ A query to check if a field starts with a given prefix string
  
              **Example**: ``session.query(Spell).filter(Spells.name.startswith("abra", ignore_case=True))``
  
              .. note:: This is a shortcut to .regex('^' + re.escape(prefix))
                  MongoDB optimises such prefix expressions to use indexes
                  appropriately. As the prefix contains no further regex, this
                  will be optimized by matching only against the prefix.
  
          """
          return self.regex('^' + re.escape(prefix), ignore_case=ignore_case, options=options)