code: def _engine_builder(con):
      
      global _SQLALCHEMY_INSTALLED
      if isinstance(con, str):
          try:
              import sqlalchemy
          except ImportError:
              _SQLALCHEMY_INSTALLED = False
          else:
              con = sqlalchemy.create_engine(con)
              return con
  
      return con
docs: Returns a SQLAlchemy engine from a URI (if con is a string)
      else it just return con without modifying it.