<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def database_all(self):
 """Return a dictionary mapping engines with databases """

        all = {}
        for engine in self.engines():
            all[engine] = self._database_all(engine)
        return all